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-rw-r--r--Documentation/arm/00-INDEX36
-rw-r--r--Documentation/arm/Booting191
-rw-r--r--Documentation/arm/IXP4xx172
-rw-r--r--Documentation/arm/Interrupts167
-rw-r--r--Documentation/arm/Marvell/README232
-rw-r--r--Documentation/arm/Netwinder78
-rw-r--r--Documentation/arm/OMAP/DSS362
-rw-r--r--Documentation/arm/OMAP/omap_pm154
-rw-r--r--Documentation/arm/Porting135
-rw-r--r--Documentation/arm/README197
-rw-r--r--Documentation/arm/SA1100/ADSBitsy43
-rw-r--r--Documentation/arm/SA1100/Assabet300
-rw-r--r--Documentation/arm/SA1100/Brutus66
-rw-r--r--Documentation/arm/SA1100/CERF29
-rw-r--r--Documentation/arm/SA1100/FreeBird21
-rw-r--r--Documentation/arm/SA1100/GraphicsClient98
-rw-r--r--Documentation/arm/SA1100/GraphicsMaster53
-rw-r--r--Documentation/arm/SA1100/HUW_WEBPANEL17
-rw-r--r--Documentation/arm/SA1100/Itsy39
-rw-r--r--Documentation/arm/SA1100/LART14
-rw-r--r--Documentation/arm/SA1100/PLEB11
-rw-r--r--Documentation/arm/SA1100/Pangolin23
-rw-r--r--Documentation/arm/SA1100/Tifon7
-rw-r--r--Documentation/arm/SA1100/Victor16
-rw-r--r--Documentation/arm/SA1100/Yopy2
-rw-r--r--Documentation/arm/SA1100/empeg2
-rw-r--r--Documentation/arm/SA1100/nanoEngine11
-rw-r--r--Documentation/arm/SA1100/serial_UART47
-rw-r--r--Documentation/arm/SH-Mobile/Makefile8
-rw-r--r--Documentation/arm/SH-Mobile/vrl4.c169
-rw-r--r--Documentation/arm/SH-Mobile/zboot-rom-mmcif.txt29
-rw-r--r--Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt42
-rw-r--r--Documentation/arm/SPEAr/overview.txt63
-rw-r--r--Documentation/arm/Samsung-S3C24XX/CPUfreq.txt75
-rw-r--r--Documentation/arm/Samsung-S3C24XX/DMA.txt46
-rw-r--r--Documentation/arm/Samsung-S3C24XX/EB2410ITX.txt58
-rw-r--r--Documentation/arm/Samsung-S3C24XX/GPIO.txt182
-rw-r--r--Documentation/arm/Samsung-S3C24XX/H1940.txt40
-rw-r--r--Documentation/arm/Samsung-S3C24XX/NAND.txt30
-rw-r--r--Documentation/arm/Samsung-S3C24XX/Overview.txt318
-rw-r--r--Documentation/arm/Samsung-S3C24XX/S3C2412.txt120
-rw-r--r--Documentation/arm/Samsung-S3C24XX/S3C2413.txt21
-rw-r--r--Documentation/arm/Samsung-S3C24XX/SMDK2440.txt56
-rw-r--r--Documentation/arm/Samsung-S3C24XX/Suspend.txt137
-rw-r--r--Documentation/arm/Samsung-S3C24XX/USB-Host.txt93
-rw-r--r--Documentation/arm/Samsung/GPIO.txt40
-rw-r--r--Documentation/arm/Samsung/Overview.txt97
-rwxr-xr-xDocumentation/arm/Samsung/clksrc-change-registers.awk167
-rw-r--r--Documentation/arm/Setup129
-rw-r--r--Documentation/arm/VFP/release-notes.txt55
-rw-r--r--Documentation/arm/cluster-pm-race-avoidance.txt498
-rw-r--r--Documentation/arm/kernel_user_helpers.txt267
-rw-r--r--Documentation/arm/mem_alignment58
-rw-r--r--Documentation/arm/memory.txt95
-rw-r--r--Documentation/arm/msm/gpiomux.txt176
-rw-r--r--Documentation/arm/nwfpe/NOTES29
-rw-r--r--Documentation/arm/nwfpe/README70
-rw-r--r--Documentation/arm/nwfpe/README.FPE156
-rw-r--r--Documentation/arm/nwfpe/TODO67
-rw-r--r--Documentation/arm/pxa/mfp.txt286
-rw-r--r--Documentation/arm/sunxi/README19
-rw-r--r--Documentation/arm/swp_emulation27
-rw-r--r--Documentation/arm/tcm.txt155
-rw-r--r--Documentation/arm/vlocks.txt211
64 files changed, 6612 insertions, 0 deletions
diff --git a/Documentation/arm/00-INDEX b/Documentation/arm/00-INDEX
new file mode 100644
index 00000000..36420e11
--- /dev/null
+++ b/Documentation/arm/00-INDEX
@@ -0,0 +1,36 @@
+00-INDEX
+ - this file
+Booting
+ - requirements for booting
+Interrupts
+ - ARM Interrupt subsystem documentation
+msm
+ - MSM specific documentation
+Netwinder
+ - Netwinder specific documentation
+Porting
+ - Symbol definitions for porting Linux to a new ARM machine.
+Setup
+ - Kernel initialization parameters on ARM Linux
+README
+ - General ARM documentation
+SA1100/
+ - SA1100 documentation
+Samsung-S3C24XX
+ - S3C24XX ARM Linux Overview
+Sharp-LH
+ - Linux on Sharp LH79524 and LH7A40X System On a Chip (SOC)
+SPEAr
+ - ST SPEAr platform Linux Overview
+VFP/
+ - Release notes for Linux Kernel Vector Floating Point support code
+empeg/
+ - Ltd's Empeg MP3 Car Audio Player
+mem_alignment
+ - alignment abort handler documentation
+memory.txt
+ - description of the virtual memory layout
+nwfpe/
+ - NWFPE floating point emulator documentation
+swp_emulation
+ - SWP/SWPB emulation handler/logging description
diff --git a/Documentation/arm/Booting b/Documentation/arm/Booting
new file mode 100644
index 00000000..0c1f475f
--- /dev/null
+++ b/Documentation/arm/Booting
@@ -0,0 +1,191 @@
+ Booting ARM Linux
+ =================
+
+Author: Russell King
+Date : 18 May 2002
+
+The following documentation is relevant to 2.4.18-rmk6 and beyond.
+
+In order to boot ARM Linux, you require a boot loader, which is a small
+program that runs before the main kernel. The boot loader is expected
+to initialise various devices, and eventually call the Linux kernel,
+passing information to the kernel.
+
+Essentially, the boot loader should provide (as a minimum) the
+following:
+
+1. Setup and initialise the RAM.
+2. Initialise one serial port.
+3. Detect the machine type.
+4. Setup the kernel tagged list.
+5. Call the kernel image.
+
+
+1. Setup and initialise RAM
+---------------------------
+
+Existing boot loaders: MANDATORY
+New boot loaders: MANDATORY
+
+The boot loader is expected to find and initialise all RAM that the
+kernel will use for volatile data storage in the system. It performs
+this in a machine dependent manner. (It may use internal algorithms
+to automatically locate and size all RAM, or it may use knowledge of
+the RAM in the machine, or any other method the boot loader designer
+sees fit.)
+
+
+2. Initialise one serial port
+-----------------------------
+
+Existing boot loaders: OPTIONAL, RECOMMENDED
+New boot loaders: OPTIONAL, RECOMMENDED
+
+The boot loader should initialise and enable one serial port on the
+target. This allows the kernel serial driver to automatically detect
+which serial port it should use for the kernel console (generally
+used for debugging purposes, or communication with the target.)
+
+As an alternative, the boot loader can pass the relevant 'console='
+option to the kernel via the tagged lists specifying the port, and
+serial format options as described in
+
+ Documentation/kernel-parameters.txt.
+
+
+3. Detect the machine type
+--------------------------
+
+Existing boot loaders: OPTIONAL
+New boot loaders: MANDATORY
+
+The boot loader should detect the machine type its running on by some
+method. Whether this is a hard coded value or some algorithm that
+looks at the connected hardware is beyond the scope of this document.
+The boot loader must ultimately be able to provide a MACH_TYPE_xxx
+value to the kernel. (see linux/arch/arm/tools/mach-types).
+
+4. Setup boot data
+------------------
+
+Existing boot loaders: OPTIONAL, HIGHLY RECOMMENDED
+New boot loaders: MANDATORY
+
+The boot loader must provide either a tagged list or a dtb image for
+passing configuration data to the kernel. The physical address of the
+boot data is passed to the kernel in register r2.
+
+4a. Setup the kernel tagged list
+--------------------------------
+
+The boot loader must create and initialise the kernel tagged list.
+A valid tagged list starts with ATAG_CORE and ends with ATAG_NONE.
+The ATAG_CORE tag may or may not be empty. An empty ATAG_CORE tag
+has the size field set to '2' (0x00000002). The ATAG_NONE must set
+the size field to zero.
+
+Any number of tags can be placed in the list. It is undefined
+whether a repeated tag appends to the information carried by the
+previous tag, or whether it replaces the information in its
+entirety; some tags behave as the former, others the latter.
+
+The boot loader must pass at a minimum the size and location of
+the system memory, and root filesystem location. Therefore, the
+minimum tagged list should look:
+
+ +-----------+
+base -> | ATAG_CORE | |
+ +-----------+ |
+ | ATAG_MEM | | increasing address
+ +-----------+ |
+ | ATAG_NONE | |
+ +-----------+ v
+
+The tagged list should be stored in system RAM.
+
+The tagged list must be placed in a region of memory where neither
+the kernel decompressor nor initrd 'bootp' program will overwrite
+it. The recommended placement is in the first 16KiB of RAM.
+
+4b. Setup the device tree
+-------------------------
+
+The boot loader must load a device tree image (dtb) into system ram
+at a 64bit aligned address and initialize it with the boot data. The
+dtb format is documented in Documentation/devicetree/booting-without-of.txt.
+The kernel will look for the dtb magic value of 0xd00dfeed at the dtb
+physical address to determine if a dtb has been passed instead of a
+tagged list.
+
+The boot loader must pass at a minimum the size and location of the
+system memory, and the root filesystem location. The dtb must be
+placed in a region of memory where the kernel decompressor will not
+overwrite it. The recommended placement is in the first 16KiB of RAM
+with the caveat that it may not be located at physical address 0 since
+the kernel interprets a value of 0 in r2 to mean neither a tagged list
+nor a dtb were passed.
+
+5. Calling the kernel image
+---------------------------
+
+Existing boot loaders: MANDATORY
+New boot loaders: MANDATORY
+
+There are two options for calling the kernel zImage. If the zImage
+is stored in flash, and is linked correctly to be run from flash,
+then it is legal for the boot loader to call the zImage in flash
+directly.
+
+The zImage may also be placed in system RAM (at any location) and
+called there. Note that the kernel uses 16K of RAM below the image
+to store page tables. The recommended placement is 32KiB into RAM.
+
+In either case, the following conditions must be met:
+
+- Quiesce all DMA capable devices so that memory does not get
+ corrupted by bogus network packets or disk data. This will save
+ you many hours of debug.
+
+- CPU register settings
+ r0 = 0,
+ r1 = machine type number discovered in (3) above.
+ r2 = physical address of tagged list in system RAM, or
+ physical address of device tree block (dtb) in system RAM
+
+- CPU mode
+ All forms of interrupts must be disabled (IRQs and FIQs)
+
+ For CPUs which do not include the ARM virtualization extensions, the
+ CPU must be in SVC mode. (A special exception exists for Angel)
+
+ CPUs which include support for the virtualization extensions can be
+ entered in HYP mode in order to enable the kernel to make full use of
+ these extensions. This is the recommended boot method for such CPUs,
+ unless the virtualisations are already in use by a pre-installed
+ hypervisor.
+
+ If the kernel is not entered in HYP mode for any reason, it must be
+ entered in SVC mode.
+
+- Caches, MMUs
+ The MMU must be off.
+ Instruction cache may be on or off.
+ Data cache must be off.
+
+ If the kernel is entered in HYP mode, the above requirements apply to
+ the HYP mode configuration in addition to the ordinary PL1 (privileged
+ kernel modes) configuration. In addition, all traps into the
+ hypervisor must be disabled, and PL1 access must be granted for all
+ peripherals and CPU resources for which this is architecturally
+ possible. Except for entering in HYP mode, the system configuration
+ should be such that a kernel which does not include support for the
+ virtualization extensions can boot correctly without extra help.
+
+- The boot loader is expected to call the kernel image by jumping
+ directly to the first instruction of the kernel image.
+
+ On CPUs supporting the ARM instruction set, the entry must be
+ made in ARM state, even for a Thumb-2 kernel.
+
+ On CPUs supporting only the Thumb instruction set such as
+ Cortex-M class CPUs, the entry must be made in Thumb state.
diff --git a/Documentation/arm/IXP4xx b/Documentation/arm/IXP4xx
new file mode 100644
index 00000000..7b9351f2
--- /dev/null
+++ b/Documentation/arm/IXP4xx
@@ -0,0 +1,172 @@
+
+-------------------------------------------------------------------------
+Release Notes for Linux on Intel's IXP4xx Network Processor
+
+Maintained by Deepak Saxena <dsaxena@plexity.net>
+-------------------------------------------------------------------------
+
+1. Overview
+
+Intel's IXP4xx network processor is a highly integrated SOC that
+is targeted for network applications, though it has become popular
+in industrial control and other areas due to low cost and power
+consumption. The IXP4xx family currently consists of several processors
+that support different network offload functions such as encryption,
+routing, firewalling, etc. The IXP46x family is an updated version which
+supports faster speeds, new memory and flash configurations, and more
+integration such as an on-chip I2C controller.
+
+For more information on the various versions of the CPU, see:
+
+ http://developer.intel.com/design/network/products/npfamily/ixp4xx.htm
+
+Intel also made the IXCP1100 CPU for sometime which is an IXP4xx
+stripped of much of the network intelligence.
+
+2. Linux Support
+
+Linux currently supports the following features on the IXP4xx chips:
+
+- Dual serial ports
+- PCI interface
+- Flash access (MTD/JFFS)
+- I2C through GPIO on IXP42x
+- GPIO for input/output/interrupts
+ See arch/arm/mach-ixp4xx/include/mach/platform.h for access functions.
+- Timers (watchdog, OS)
+
+The following components of the chips are not supported by Linux and
+require the use of Intel's proprietary CSR softare:
+
+- USB device interface
+- Network interfaces (HSS, Utopia, NPEs, etc)
+- Network offload functionality
+
+If you need to use any of the above, you need to download Intel's
+software from:
+
+ http://developer.intel.com/design/network/products/npfamily/ixp425.htm
+
+DO NOT POST QUESTIONS TO THE LINUX MAILING LISTS REGARDING THE PROPRIETARY
+SOFTWARE.
+
+There are several websites that provide directions/pointers on using
+Intel's software:
+
+ http://sourceforge.net/projects/ixp4xx-osdg/
+ Open Source Developer's Guide for using uClinux and the Intel libraries
+
+http://gatewaymaker.sourceforge.net/
+ Simple one page summary of building a gateway using an IXP425 and Linux
+
+http://ixp425.sourceforge.net/
+ ATM device driver for IXP425 that relies on Intel's libraries
+
+3. Known Issues/Limitations
+
+3a. Limited inbound PCI window
+
+The IXP4xx family allows for up to 256MB of memory but the PCI interface
+can only expose 64MB of that memory to the PCI bus. This means that if
+you are running with > 64MB, all PCI buffers outside of the accessible
+range will be bounced using the routines in arch/arm/common/dmabounce.c.
+
+3b. Limited outbound PCI window
+
+IXP4xx provides two methods of accessing PCI memory space:
+
+1) A direct mapped window from 0x48000000 to 0x4bffffff (64MB).
+ To access PCI via this space, we simply ioremap() the BAR
+ into the kernel and we can use the standard read[bwl]/write[bwl]
+ macros. This is the preffered method due to speed but it
+ limits the system to just 64MB of PCI memory. This can be
+ problamatic if using video cards and other memory-heavy devices.
+
+2) If > 64MB of memory space is required, the IXP4xx can be
+ configured to use indirect registers to access PCI This allows
+ for up to 128MB (0x48000000 to 0x4fffffff) of memory on the bus.
+ The disadvantage of this is that every PCI access requires
+ three local register accesses plus a spinlock, but in some
+ cases the performance hit is acceptable. In addition, you cannot
+ mmap() PCI devices in this case due to the indirect nature
+ of the PCI window.
+
+By default, the direct method is used for performance reasons. If
+you need more PCI memory, enable the IXP4XX_INDIRECT_PCI config option.
+
+3c. GPIO as Interrupts
+
+Currently the code only handles level-sensitive GPIO interrupts
+
+4. Supported platforms
+
+ADI Engineering Coyote Gateway Reference Platform
+http://www.adiengineering.com/productsCoyote.html
+
+ The ADI Coyote platform is reference design for those building
+ small residential/office gateways. One NPE is connected to a 10/100
+ interface, one to 4-port 10/100 switch, and the third to and ADSL
+ interface. In addition, it also supports to POTs interfaces connected
+ via SLICs. Note that those are not supported by Linux ATM. Finally,
+ the platform has two mini-PCI slots used for 802.11[bga] cards.
+ Finally, there is an IDE port hanging off the expansion bus.
+
+Gateworks Avila Network Platform
+http://www.gateworks.com/support/overview.php
+
+ The Avila platform is basically and IXDP425 with the 4 PCI slots
+ replaced with mini-PCI slots and a CF IDE interface hanging off
+ the expansion bus.
+
+Intel IXDP425 Development Platform
+http://www.intel.com/design/network/products/npfamily/ixdpg425.htm
+
+ This is Intel's standard reference platform for the IXDP425 and is
+ also known as the Richfield board. It contains 4 PCI slots, 16MB
+ of flash, two 10/100 ports and one ADSL port.
+
+Intel IXDP465 Development Platform
+http://www.intel.com/design/network/products/npfamily/ixdp465.htm
+
+ This is basically an IXDP425 with an IXP465 and 32M of flash instead
+ of just 16.
+
+Intel IXDPG425 Development Platform
+
+ This is basically and ADI Coyote board with a NEC EHCI controller
+ added. One issue with this board is that the mini-PCI slots only
+ have the 3.3v line connected, so you can't use a PCI to mini-PCI
+ adapter with an E100 card. So to NFS root you need to use either
+ the CSR or a WiFi card and a ramdisk that BOOTPs and then does
+ a pivot_root to NFS.
+
+Motorola PrPMC1100 Processor Mezanine Card
+http://www.fountainsys.com
+
+ The PrPMC1100 is based on the IXCP1100 and is meant to plug into
+ and IXP2400/2800 system to act as the system controller. It simply
+ contains a CPU and 16MB of flash on the board and needs to be
+ plugged into a carrier board to function. Currently Linux only
+ supports the Motorola PrPMC carrier board for this platform.
+
+5. TODO LIST
+
+- Add support for Coyote IDE
+- Add support for edge-based GPIO interrupts
+- Add support for CF IDE on expansion bus
+
+6. Thanks
+
+The IXP4xx work has been funded by Intel Corp. and MontaVista Software, Inc.
+
+The following people have contributed patches/comments/etc:
+
+Lennerty Buytenhek
+Lutz Jaenicke
+Justin Mayfield
+Robert E. Ranslam
+[I know I've forgotten others, please email me to be added]
+
+-------------------------------------------------------------------------
+
+Last Update: 01/04/2005
diff --git a/Documentation/arm/Interrupts b/Documentation/arm/Interrupts
new file mode 100644
index 00000000..f09ab1b9
--- /dev/null
+++ b/Documentation/arm/Interrupts
@@ -0,0 +1,167 @@
+2.5.2-rmk5
+----------
+
+This is the first kernel that contains a major shake up of some of the
+major architecture-specific subsystems.
+
+Firstly, it contains some pretty major changes to the way we handle the
+MMU TLB. Each MMU TLB variant is now handled completely separately -
+we have TLB v3, TLB v4 (without write buffer), TLB v4 (with write buffer),
+and finally TLB v4 (with write buffer, with I TLB invalidate entry).
+There is more assembly code inside each of these functions, mainly to
+allow more flexible TLB handling for the future.
+
+Secondly, the IRQ subsystem.
+
+The 2.5 kernels will be having major changes to the way IRQs are handled.
+Unfortunately, this means that machine types that touch the irq_desc[]
+array (basically all machine types) will break, and this means every
+machine type that we currently have.
+
+Lets take an example. On the Assabet with Neponset, we have:
+
+ GPIO25 IRR:2
+ SA1100 ------------> Neponset -----------> SA1111
+ IIR:1
+ -----------> USAR
+ IIR:0
+ -----------> SMC9196
+
+The way stuff currently works, all SA1111 interrupts are mutually
+exclusive of each other - if you're processing one interrupt from the
+SA1111 and another comes in, you have to wait for that interrupt to
+finish processing before you can service the new interrupt. Eg, an
+IDE PIO-based interrupt on the SA1111 excludes all other SA1111 and
+SMC9196 interrupts until it has finished transferring its multi-sector
+data, which can be a long time. Note also that since we loop in the
+SA1111 IRQ handler, SA1111 IRQs can hold off SMC9196 IRQs indefinitely.
+
+
+The new approach brings several new ideas...
+
+We introduce the concept of a "parent" and a "child". For example,
+to the Neponset handler, the "parent" is GPIO25, and the "children"d
+are SA1111, SMC9196 and USAR.
+
+We also bring the idea of an IRQ "chip" (mainly to reduce the size of
+the irqdesc array). This doesn't have to be a real "IC"; indeed the
+SA11x0 IRQs are handled by two separate "chip" structures, one for
+GPIO0-10, and another for all the rest. It is just a container for
+the various operations (maybe this'll change to a better name).
+This structure has the following operations:
+
+struct irqchip {
+ /*
+ * Acknowledge the IRQ.
+ * If this is a level-based IRQ, then it is expected to mask the IRQ
+ * as well.
+ */
+ void (*ack)(unsigned int irq);
+ /*
+ * Mask the IRQ in hardware.
+ */
+ void (*mask)(unsigned int irq);
+ /*
+ * Unmask the IRQ in hardware.
+ */
+ void (*unmask)(unsigned int irq);
+ /*
+ * Re-run the IRQ
+ */
+ void (*rerun)(unsigned int irq);
+ /*
+ * Set the type of the IRQ.
+ */
+ int (*type)(unsigned int irq, unsigned int, type);
+};
+
+ack - required. May be the same function as mask for IRQs
+ handled by do_level_IRQ.
+mask - required.
+unmask - required.
+rerun - optional. Not required if you're using do_level_IRQ for all
+ IRQs that use this 'irqchip'. Generally expected to re-trigger
+ the hardware IRQ if possible. If not, may call the handler
+ directly.
+type - optional. If you don't support changing the type of an IRQ,
+ it should be null so people can detect if they are unable to
+ set the IRQ type.
+
+For each IRQ, we keep the following information:
+
+ - "disable" depth (number of disable_irq()s without enable_irq()s)
+ - flags indicating what we can do with this IRQ (valid, probe,
+ noautounmask) as before
+ - status of the IRQ (probing, enable, etc)
+ - chip
+ - per-IRQ handler
+ - irqaction structure list
+
+The handler can be one of the 3 standard handlers - "level", "edge" and
+"simple", or your own specific handler if you need to do something special.
+
+The "level" handler is what we currently have - its pretty simple.
+"edge" knows about the brokenness of such IRQ implementations - that you
+need to leave the hardware IRQ enabled while processing it, and queueing
+further IRQ events should the IRQ happen again while processing. The
+"simple" handler is very basic, and does not perform any hardware
+manipulation, nor state tracking. This is useful for things like the
+SMC9196 and USAR above.
+
+So, what's changed?
+
+1. Machine implementations must not write to the irqdesc array.
+
+2. New functions to manipulate the irqdesc array. The first 4 are expected
+ to be useful only to machine specific code. The last is recommended to
+ only be used by machine specific code, but may be used in drivers if
+ absolutely necessary.
+
+ set_irq_chip(irq,chip)
+
+ Set the mask/unmask methods for handling this IRQ
+
+ set_irq_handler(irq,handler)
+
+ Set the handler for this IRQ (level, edge, simple)
+
+ set_irq_chained_handler(irq,handler)
+
+ Set a "chained" handler for this IRQ - automatically
+ enables this IRQ (eg, Neponset and SA1111 handlers).
+
+ set_irq_flags(irq,flags)
+
+ Set the valid/probe/noautoenable flags.
+
+ set_irq_type(irq,type)
+
+ Set active the IRQ edge(s)/level. This replaces the
+ SA1111 INTPOL manipulation, and the set_GPIO_IRQ_edge()
+ function. Type should be one of IRQ_TYPE_xxx defined in
+ <linux/irq.h>
+
+3. set_GPIO_IRQ_edge() is obsolete, and should be replaced by set_irq_type.
+
+4. Direct access to SA1111 INTPOL is deprecated. Use set_irq_type instead.
+
+5. A handler is expected to perform any necessary acknowledgement of the
+ parent IRQ via the correct chip specific function. For instance, if
+ the SA1111 is directly connected to a SA1110 GPIO, then you should
+ acknowledge the SA1110 IRQ each time you re-read the SA1111 IRQ status.
+
+6. For any child which doesn't have its own IRQ enable/disable controls
+ (eg, SMC9196), the handler must mask or acknowledge the parent IRQ
+ while the child handler is called, and the child handler should be the
+ "simple" handler (not "edge" nor "level"). After the handler completes,
+ the parent IRQ should be unmasked, and the status of all children must
+ be re-checked for pending events. (see the Neponset IRQ handler for
+ details).
+
+7. fixup_irq() is gone, as is arch/arm/mach-*/include/mach/irq.h
+
+Please note that this will not solve all problems - some of them are
+hardware based. Mixing level-based and edge-based IRQs on the same
+parent signal (eg neponset) is one such area where a software based
+solution can't provide the full answer to low IRQ latency.
+
diff --git a/Documentation/arm/Marvell/README b/Documentation/arm/Marvell/README
new file mode 100644
index 00000000..8f08a86e
--- /dev/null
+++ b/Documentation/arm/Marvell/README
@@ -0,0 +1,232 @@
+ARM Marvell SoCs
+================
+
+This document lists all the ARM Marvell SoCs that are currently
+supported in mainline by the Linux kernel. As the Marvell families of
+SoCs are large and complex, it is hard to understand where the support
+for a particular SoC is available in the Linux kernel. This document
+tries to help in understanding where those SoCs are supported, and to
+match them with their corresponding public datasheet, when available.
+
+Orion family
+------------
+
+ Flavors:
+ 88F5082
+ 88F5181
+ 88F5181L
+ 88F5182
+ Datasheet : http://www.embeddedarm.com/documentation/third-party/MV88F5182-datasheet.pdf
+ Programmer's User Guide : http://www.embeddedarm.com/documentation/third-party/MV88F5182-opensource-manual.pdf
+ User Manual : http://www.embeddedarm.com/documentation/third-party/MV88F5182-usermanual.pdf
+ 88F5281
+ Datasheet : http://www.ocmodshop.com/images/reviews/networking/qnap_ts409u/marvel_88f5281_data_sheet.pdf
+ 88F6183
+ Core: Feroceon ARMv5 compatible
+ Linux kernel mach directory: arch/arm/mach-orion5x
+ Linux kernel plat directory: arch/arm/plat-orion
+
+Kirkwood family
+---------------
+
+ Flavors:
+ 88F6282 a.k.a Armada 300
+ Product Brief : http://www.marvell.com/embedded-processors/armada-300/assets/armada_310.pdf
+ 88F6283 a.k.a Armada 310
+ Product Brief : http://www.marvell.com/embedded-processors/armada-300/assets/armada_310.pdf
+ 88F6190
+ Product Brief : http://www.marvell.com/embedded-processors/kirkwood/assets/88F6190-003_WEB.pdf
+ Hardware Spec : http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F619x_OpenSource.pdf
+ Functional Spec: http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf
+ 88F6192
+ Product Brief : http://www.marvell.com/embedded-processors/kirkwood/assets/88F6192-003_ver1.pdf
+ Hardware Spec : http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F619x_OpenSource.pdf
+ Functional Spec: http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf
+ 88F6182
+ 88F6180
+ Product Brief : http://www.marvell.com/embedded-processors/kirkwood/assets/88F6180-003_ver1.pdf
+ Hardware Spec : http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F6180_OpenSource.pdf
+ Functional Spec: http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf
+ 88F6281
+ Product Brief : http://www.marvell.com/embedded-processors/kirkwood/assets/88F6281-004_ver1.pdf
+ Hardware Spec : http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F6281_OpenSource.pdf
+ Functional Spec: http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf
+ Homepage: http://www.marvell.com/embedded-processors/kirkwood/
+ Core: Feroceon ARMv5 compatible
+ Linux kernel mach directory: arch/arm/mach-kirkwood
+ Linux kernel plat directory: arch/arm/plat-orion
+
+Discovery family
+----------------
+
+ Flavors:
+ MV78100
+ Product Brief : http://www.marvell.com/embedded-processors/discovery-innovation/assets/MV78100-003_WEB.pdf
+ Hardware Spec : http://www.marvell.com/embedded-processors/discovery-innovation/assets/HW_MV78100_OpenSource.pdf
+ Functional Spec: http://www.marvell.com/embedded-processors/discovery-innovation/assets/FS_MV76100_78100_78200_OpenSource.pdf
+ MV78200
+ Product Brief : http://www.marvell.com/embedded-processors/discovery-innovation/assets/MV78200-002_WEB.pdf
+ Hardware Spec : http://www.marvell.com/embedded-processors/discovery-innovation/assets/HW_MV78200_OpenSource.pdf
+ Functional Spec: http://www.marvell.com/embedded-processors/discovery-innovation/assets/FS_MV76100_78100_78200_OpenSource.pdf
+ MV76100
+ Not supported by the Linux kernel.
+
+ Core: Feroceon ARMv5 compatible
+
+ Linux kernel mach directory: arch/arm/mach-mv78xx0
+ Linux kernel plat directory: arch/arm/plat-orion
+
+EBU Armada family
+-----------------
+
+ Armada 370 Flavors:
+ 88F6710
+ 88F6707
+ 88F6W11
+
+ Armada XP Flavors:
+ MV78230
+ MV78260
+ MV78460
+
+ Product Brief: http://www.marvell.com/embedded-processors/armada-xp/assets/Marvell-ArmadaXP-SoC-product%20brief.pdf
+ No public datasheet available.
+
+ Core: Sheeva ARMv7 compatible
+
+ Linux kernel mach directory: arch/arm/mach-mvebu
+ Linux kernel plat directory: none
+
+Avanta family
+-------------
+
+ Flavors:
+ 88F6510
+ 88F6530P
+ 88F6550
+ 88F6560
+ Homepage : http://www.marvell.com/broadband/
+ Product Brief: http://www.marvell.com/broadband/assets/Marvell_Avanta_88F6510_305_060-001_product_brief.pdf
+ No public datasheet available.
+
+ Core: ARMv5 compatible
+
+ Linux kernel mach directory: no code in mainline yet, planned for the future
+ Linux kernel plat directory: no code in mainline yet, planned for the future
+
+Dove family (application processor)
+-----------------------------------
+
+ Flavors:
+ 88AP510 a.k.a Armada 510
+ Product Brief : http://www.marvell.com/application-processors/armada-500/assets/Marvell_Armada510_SoC.pdf
+ Hardware Spec : http://www.marvell.com/application-processors/armada-500/assets/Armada-510-Hardware-Spec.pdf
+ Functional Spec : http://www.marvell.com/application-processors/armada-500/assets/Armada-510-Functional-Spec.pdf
+ Homepage: http://www.marvell.com/application-processors/armada-500/
+ Core: ARMv7 compatible
+ Directory: arch/arm/mach-dove
+
+PXA 2xx/3xx/93x/95x family
+--------------------------
+
+ Flavors:
+ PXA21x, PXA25x, PXA26x
+ Application processor only
+ Core: ARMv5 XScale core
+ PXA270, PXA271, PXA272
+ Product Brief : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_pb.pdf
+ Design guide : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_design_guide.pdf
+ Developers manual : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_dev_man.pdf
+ Specification : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_emts.pdf
+ Specification update : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_spec_update.pdf
+ Application processor only
+ Core: ARMv5 XScale core
+ PXA300, PXA310, PXA320
+ PXA 300 Product Brief : http://www.marvell.com/application-processors/pxa-family/assets/PXA300_PB_R4.pdf
+ PXA 310 Product Brief : http://www.marvell.com/application-processors/pxa-family/assets/PXA310_PB_R4.pdf
+ PXA 320 Product Brief : http://www.marvell.com/application-processors/pxa-family/assets/PXA320_PB_R4.pdf
+ Design guide : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_Design_Guide.pdf
+ Developers manual : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_Developers_Manual.zip
+ Specifications : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_EMTS.pdf
+ Specification Update : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_Spec_Update.zip
+ Reference Manual : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_TavorP_BootROM_Ref_Manual.pdf
+ Application processor only
+ Core: ARMv5 XScale core
+ PXA930, PXA935
+ Application processor with Communication processor
+ Core: ARMv5 XScale core
+ PXA955
+ Application processor with Communication processor
+ Core: ARMv7 compatible Sheeva PJ4 core
+
+ Comments:
+
+ * This line of SoCs originates from the XScale family developed by
+ Intel and acquired by Marvell in ~2006. The PXA21x, PXA25x,
+ PXA26x, PXA27x, PXA3xx and PXA93x were developed by Intel, while
+ the later PXA95x were developed by Marvell.
+
+ * Due to their XScale origin, these SoCs have virtually nothing in
+ common with the other (Kirkwood, Dove, etc.) families of Marvell
+ SoCs, except with the MMP/MMP2 family of SoCs.
+
+ Linux kernel mach directory: arch/arm/mach-pxa
+ Linux kernel plat directory: arch/arm/plat-pxa
+
+MMP/MMP2 family (communication processor)
+-----------------------------------------
+
+ Flavors:
+ PXA168, a.k.a Armada 168
+ Homepage : http://www.marvell.com/application-processors/armada-100/armada-168.jsp
+ Product brief : http://www.marvell.com/application-processors/armada-100/assets/pxa_168_pb.pdf
+ Hardware manual : http://www.marvell.com/application-processors/armada-100/assets/armada_16x_datasheet.pdf
+ Software manual : http://www.marvell.com/application-processors/armada-100/assets/armada_16x_software_manual.pdf
+ Specification update : http://www.marvell.com/application-processors/armada-100/assets/ARMADA16x_Spec_update.pdf
+ Boot ROM manual : http://www.marvell.com/application-processors/armada-100/assets/armada_16x_ref_manual.pdf
+ App node package : http://www.marvell.com/application-processors/armada-100/assets/armada_16x_app_note_package.pdf
+ Application processor only
+ Core: ARMv5 compatible Marvell PJ1 (Mohawk)
+ PXA910
+ Homepage : http://www.marvell.com/communication-processors/pxa910/
+ Product Brief : http://www.marvell.com/communication-processors/pxa910/assets/Marvell_PXA910_Platform-001_PB_final.pdf
+ Application processor with Communication processor
+ Core: ARMv5 compatible Marvell PJ1 (Mohawk)
+ MMP2, a.k.a Armada 610
+ Product Brief : http://www.marvell.com/application-processors/armada-600/assets/armada610_pb.pdf
+ Application processor only
+ Core: ARMv7 compatible Sheeva PJ4 core
+
+ Comments:
+
+ * This line of SoCs originates from the XScale family developed by
+ Intel and acquired by Marvell in ~2006. All the processors of
+ this MMP/MMP2 family were developed by Marvell.
+
+ * Due to their XScale origin, these SoCs have virtually nothing in
+ common with the other (Kirkwood, Dove, etc.) families of Marvell
+ SoCs, except with the PXA family of SoCs listed above.
+
+ Linux kernel mach directory: arch/arm/mach-mmp
+ Linux kernel plat directory: arch/arm/plat-pxa
+
+Long-term plans
+---------------
+
+ * Unify the mach-dove/, mach-mv78xx0/, mach-orion5x/ and
+ mach-kirkwood/ into the mach-mvebu/ to support all SoCs from the
+ Marvell EBU (Engineering Business Unit) in a single mach-<foo>
+ directory. The plat-orion/ would therefore disappear.
+
+ * Unify the mach-mmp/ and mach-pxa/ into the same mach-pxa
+ directory. The plat-pxa/ would therefore disappear.
+
+Credits
+-------
+
+ Maen Suleiman <maen@marvell.com>
+ Lior Amsalem <alior@marvell.com>
+ Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ Andrew Lunn <andrew@lunn.ch>
+ Nicolas Pitre <nico@fluxnic.net>
+ Eric Miao <eric.y.miao@gmail.com>
diff --git a/Documentation/arm/Netwinder b/Documentation/arm/Netwinder
new file mode 100644
index 00000000..f1b457fb
--- /dev/null
+++ b/Documentation/arm/Netwinder
@@ -0,0 +1,78 @@
+NetWinder specific documentation
+================================
+
+The NetWinder is a small low-power computer, primarily designed
+to run Linux. It is based around the StrongARM RISC processor,
+DC21285 PCI bridge, with PC-type hardware glued around it.
+
+Port usage
+==========
+
+Min - Max Description
+---------------------------
+0x0000 - 0x000f DMA1
+0x0020 - 0x0021 PIC1
+0x0060 - 0x006f Keyboard
+0x0070 - 0x007f RTC
+0x0080 - 0x0087 DMA1
+0x0088 - 0x008f DMA2
+0x00a0 - 0x00a3 PIC2
+0x00c0 - 0x00df DMA2
+0x0180 - 0x0187 IRDA
+0x01f0 - 0x01f6 ide0
+0x0201 Game port
+0x0203 RWA010 configuration read
+0x0220 - ? SoundBlaster
+0x0250 - ? WaveArtist
+0x0279 RWA010 configuration index
+0x02f8 - 0x02ff Serial ttyS1
+0x0300 - 0x031f Ether10
+0x0338 GPIO1
+0x033a GPIO2
+0x0370 - 0x0371 W83977F configuration registers
+0x0388 - ? AdLib
+0x03c0 - 0x03df VGA
+0x03f6 ide0
+0x03f8 - 0x03ff Serial ttyS0
+0x0400 - 0x0408 DC21143
+0x0480 - 0x0487 DMA1
+0x0488 - 0x048f DMA2
+0x0a79 RWA010 configuration write
+0xe800 - 0xe80f ide0/ide1 BM DMA
+
+
+Interrupt usage
+===============
+
+IRQ type Description
+---------------------------
+ 0 ISA 100Hz timer
+ 1 ISA Keyboard
+ 2 ISA cascade
+ 3 ISA Serial ttyS1
+ 4 ISA Serial ttyS0
+ 5 ISA PS/2 mouse
+ 6 ISA IRDA
+ 7 ISA Printer
+ 8 ISA RTC alarm
+ 9 ISA
+10 ISA GP10 (Orange reset button)
+11 ISA
+12 ISA WaveArtist
+13 ISA
+14 ISA hda1
+15 ISA
+
+DMA usage
+=========
+
+DMA type Description
+---------------------------
+ 0 ISA IRDA
+ 1 ISA
+ 2 ISA cascade
+ 3 ISA WaveArtist
+ 4 ISA
+ 5 ISA
+ 6 ISA
+ 7 ISA WaveArtist
diff --git a/Documentation/arm/OMAP/DSS b/Documentation/arm/OMAP/DSS
new file mode 100644
index 00000000..4484e021
--- /dev/null
+++ b/Documentation/arm/OMAP/DSS
@@ -0,0 +1,362 @@
+OMAP2/3 Display Subsystem
+-------------------------
+
+This is an almost total rewrite of the OMAP FB driver in drivers/video/omap
+(let's call it DSS1). The main differences between DSS1 and DSS2 are DSI,
+TV-out and multiple display support, but there are lots of small improvements
+also.
+
+The DSS2 driver (omapdss module) is in arch/arm/plat-omap/dss/, and the FB,
+panel and controller drivers are in drivers/video/omap2/. DSS1 and DSS2 live
+currently side by side, you can choose which one to use.
+
+Features
+--------
+
+Working and tested features include:
+
+- MIPI DPI (parallel) output
+- MIPI DSI output in command mode
+- MIPI DBI (RFBI) output
+- SDI output
+- TV output
+- All pieces can be compiled as a module or inside kernel
+- Use DISPC to update any of the outputs
+- Use CPU to update RFBI or DSI output
+- OMAP DISPC planes
+- RGB16, RGB24 packed, RGB24 unpacked
+- YUV2, UYVY
+- Scaling
+- Adjusting DSS FCK to find a good pixel clock
+- Use DSI DPLL to create DSS FCK
+
+Tested boards include:
+- OMAP3 SDP board
+- Beagle board
+- N810
+
+omapdss driver
+--------------
+
+The DSS driver does not itself have any support for Linux framebuffer, V4L or
+such like the current ones, but it has an internal kernel API that upper level
+drivers can use.
+
+The DSS driver models OMAP's overlays, overlay managers and displays in a
+flexible way to enable non-common multi-display configuration. In addition to
+modelling the hardware overlays, omapdss supports virtual overlays and overlay
+managers. These can be used when updating a display with CPU or system DMA.
+
+omapdss driver support for audio
+--------------------------------
+There exist several display technologies and standards that support audio as
+well. Hence, it is relevant to update the DSS device driver to provide an audio
+interface that may be used by an audio driver or any other driver interested in
+the functionality.
+
+The audio_enable function is intended to prepare the relevant
+IP for playback (e.g., enabling an audio FIFO, taking in/out of reset
+some IP, enabling companion chips, etc). It is intended to be called before
+audio_start. The audio_disable function performs the reverse operation and is
+intended to be called after audio_stop.
+
+While a given DSS device driver may support audio, it is possible that for
+certain configurations audio is not supported (e.g., an HDMI display using a
+VESA video timing). The audio_supported function is intended to query whether
+the current configuration of the display supports audio.
+
+The audio_config function is intended to configure all the relevant audio
+parameters of the display. In order to make the function independent of any
+specific DSS device driver, a struct omap_dss_audio is defined. Its purpose
+is to contain all the required parameters for audio configuration. At the
+moment, such structure contains pointers to IEC-60958 channel status word
+and CEA-861 audio infoframe structures. This should be enough to support
+HDMI and DisplayPort, as both are based on CEA-861 and IEC-60958.
+
+The audio_enable/disable, audio_config and audio_supported functions could be
+implemented as functions that may sleep. Hence, they should not be called
+while holding a spinlock or a readlock.
+
+The audio_start/audio_stop function is intended to effectively start/stop audio
+playback after the configuration has taken place. These functions are designed
+to be used in an atomic context. Hence, audio_start should return quickly and be
+called only after all the needed resources for audio playback (audio FIFOs,
+DMA channels, companion chips, etc) have been enabled to begin data transfers.
+audio_stop is designed to only stop the audio transfers. The resources used
+for playback are released using audio_disable.
+
+The enum omap_dss_audio_state may be used to help the implementations of
+the interface to keep track of the audio state. The initial state is _DISABLED;
+then, the state transitions to _CONFIGURED, and then, when it is ready to
+play audio, to _ENABLED. The state _PLAYING is used when the audio is being
+rendered.
+
+
+Panel and controller drivers
+----------------------------
+
+The drivers implement panel or controller specific functionality and are not
+usually visible to users except through omapfb driver. They register
+themselves to the DSS driver.
+
+omapfb driver
+-------------
+
+The omapfb driver implements arbitrary number of standard linux framebuffers.
+These framebuffers can be routed flexibly to any overlays, thus allowing very
+dynamic display architecture.
+
+The driver exports some omapfb specific ioctls, which are compatible with the
+ioctls in the old driver.
+
+The rest of the non standard features are exported via sysfs. Whether the final
+implementation will use sysfs, or ioctls, is still open.
+
+V4L2 drivers
+------------
+
+V4L2 is being implemented in TI.
+
+From omapdss point of view the V4L2 drivers should be similar to framebuffer
+driver.
+
+Architecture
+--------------------
+
+Some clarification what the different components do:
+
+ - Framebuffer is a memory area inside OMAP's SRAM/SDRAM that contains the
+ pixel data for the image. Framebuffer has width and height and color
+ depth.
+ - Overlay defines where the pixels are read from and where they go on the
+ screen. The overlay may be smaller than framebuffer, thus displaying only
+ part of the framebuffer. The position of the overlay may be changed if
+ the overlay is smaller than the display.
+ - Overlay manager combines the overlays in to one image and feeds them to
+ display.
+ - Display is the actual physical display device.
+
+A framebuffer can be connected to multiple overlays to show the same pixel data
+on all of the overlays. Note that in this case the overlay input sizes must be
+the same, but, in case of video overlays, the output size can be different. Any
+framebuffer can be connected to any overlay.
+
+An overlay can be connected to one overlay manager. Also DISPC overlays can be
+connected only to DISPC overlay managers, and virtual overlays can be only
+connected to virtual overlays.
+
+An overlay manager can be connected to one display. There are certain
+restrictions which kinds of displays an overlay manager can be connected:
+
+ - DISPC TV overlay manager can be only connected to TV display.
+ - Virtual overlay managers can only be connected to DBI or DSI displays.
+ - DISPC LCD overlay manager can be connected to all displays, except TV
+ display.
+
+Sysfs
+-----
+The sysfs interface is mainly used for testing. I don't think sysfs
+interface is the best for this in the final version, but I don't quite know
+what would be the best interfaces for these things.
+
+The sysfs interface is divided to two parts: DSS and FB.
+
+/sys/class/graphics/fb? directory:
+mirror 0=off, 1=on
+rotate Rotation 0-3 for 0, 90, 180, 270 degrees
+rotate_type 0 = DMA rotation, 1 = VRFB rotation
+overlays List of overlay numbers to which framebuffer pixels go
+phys_addr Physical address of the framebuffer
+virt_addr Virtual address of the framebuffer
+size Size of the framebuffer
+
+/sys/devices/platform/omapdss/overlay? directory:
+enabled 0=off, 1=on
+input_size width,height (ie. the framebuffer size)
+manager Destination overlay manager name
+name
+output_size width,height
+position x,y
+screen_width width
+global_alpha global alpha 0-255 0=transparent 255=opaque
+
+/sys/devices/platform/omapdss/manager? directory:
+display Destination display
+name
+alpha_blending_enabled 0=off, 1=on
+trans_key_enabled 0=off, 1=on
+trans_key_type gfx-destination, video-source
+trans_key_value transparency color key (RGB24)
+default_color default background color (RGB24)
+
+/sys/devices/platform/omapdss/display? directory:
+ctrl_name Controller name
+mirror 0=off, 1=on
+update_mode 0=off, 1=auto, 2=manual
+enabled 0=off, 1=on
+name
+rotate Rotation 0-3 for 0, 90, 180, 270 degrees
+timings Display timings (pixclock,xres/hfp/hbp/hsw,yres/vfp/vbp/vsw)
+ When writing, two special timings are accepted for tv-out:
+ "pal" and "ntsc"
+panel_name
+tear_elim Tearing elimination 0=off, 1=on
+output_type Output type (video encoder only): "composite" or "svideo"
+
+There are also some debugfs files at <debugfs>/omapdss/ which show information
+about clocks and registers.
+
+Examples
+--------
+
+The following definitions have been made for the examples below:
+
+ovl0=/sys/devices/platform/omapdss/overlay0
+ovl1=/sys/devices/platform/omapdss/overlay1
+ovl2=/sys/devices/platform/omapdss/overlay2
+
+mgr0=/sys/devices/platform/omapdss/manager0
+mgr1=/sys/devices/platform/omapdss/manager1
+
+lcd=/sys/devices/platform/omapdss/display0
+dvi=/sys/devices/platform/omapdss/display1
+tv=/sys/devices/platform/omapdss/display2
+
+fb0=/sys/class/graphics/fb0
+fb1=/sys/class/graphics/fb1
+fb2=/sys/class/graphics/fb2
+
+Default setup on OMAP3 SDP
+--------------------------
+
+Here's the default setup on OMAP3 SDP board. All planes go to LCD. DVI
+and TV-out are not in use. The columns from left to right are:
+framebuffers, overlays, overlay managers, displays. Framebuffers are
+handled by omapfb, and the rest by the DSS.
+
+FB0 --- GFX -\ DVI
+FB1 --- VID1 --+- LCD ---- LCD
+FB2 --- VID2 -/ TV ----- TV
+
+Example: Switch from LCD to DVI
+----------------------
+
+w=`cat $dvi/timings | cut -d "," -f 2 | cut -d "/" -f 1`
+h=`cat $dvi/timings | cut -d "," -f 3 | cut -d "/" -f 1`
+
+echo "0" > $lcd/enabled
+echo "" > $mgr0/display
+fbset -fb /dev/fb0 -xres $w -yres $h -vxres $w -vyres $h
+# at this point you have to switch the dvi/lcd dip-switch from the omap board
+echo "dvi" > $mgr0/display
+echo "1" > $dvi/enabled
+
+After this the configuration looks like:
+
+FB0 --- GFX -\ -- DVI
+FB1 --- VID1 --+- LCD -/ LCD
+FB2 --- VID2 -/ TV ----- TV
+
+Example: Clone GFX overlay to LCD and TV
+-------------------------------
+
+w=`cat $tv/timings | cut -d "," -f 2 | cut -d "/" -f 1`
+h=`cat $tv/timings | cut -d "," -f 3 | cut -d "/" -f 1`
+
+echo "0" > $ovl0/enabled
+echo "0" > $ovl1/enabled
+
+echo "" > $fb1/overlays
+echo "0,1" > $fb0/overlays
+
+echo "$w,$h" > $ovl1/output_size
+echo "tv" > $ovl1/manager
+
+echo "1" > $ovl0/enabled
+echo "1" > $ovl1/enabled
+
+echo "1" > $tv/enabled
+
+After this the configuration looks like (only relevant parts shown):
+
+FB0 +-- GFX ---- LCD ---- LCD
+ \- VID1 ---- TV ---- TV
+
+Misc notes
+----------
+
+OMAP FB allocates the framebuffer memory using the standard dma allocator. You
+can enable Contiguous Memory Allocator (CONFIG_CMA) to improve the dma
+allocator, and if CMA is enabled, you use "cma=" kernel parameter to increase
+the global memory area for CMA.
+
+Using DSI DPLL to generate pixel clock it is possible produce the pixel clock
+of 86.5MHz (max possible), and with that you get 1280x1024@57 output from DVI.
+
+Rotation and mirroring currently only supports RGB565 and RGB8888 modes. VRFB
+does not support mirroring.
+
+VRFB rotation requires much more memory than non-rotated framebuffer, so you
+probably need to increase your vram setting before using VRFB rotation. Also,
+many applications may not work with VRFB if they do not pay attention to all
+framebuffer parameters.
+
+Kernel boot arguments
+---------------------
+
+omapfb.mode=<display>:<mode>[,...]
+ - Default video mode for specified displays. For example,
+ "dvi:800x400MR-24@60". See drivers/video/modedb.c.
+ There are also two special modes: "pal" and "ntsc" that
+ can be used to tv out.
+
+omapfb.vram=<fbnum>:<size>[@<physaddr>][,...]
+ - VRAM allocated for a framebuffer. Normally omapfb allocates vram
+ depending on the display size. With this you can manually allocate
+ more or define the physical address of each framebuffer. For example,
+ "1:4M" to allocate 4M for fb1.
+
+omapfb.debug=<y|n>
+ - Enable debug printing. You have to have OMAPFB debug support enabled
+ in kernel config.
+
+omapfb.test=<y|n>
+ - Draw test pattern to framebuffer whenever framebuffer settings change.
+ You need to have OMAPFB debug support enabled in kernel config.
+
+omapfb.vrfb=<y|n>
+ - Use VRFB rotation for all framebuffers.
+
+omapfb.rotate=<angle>
+ - Default rotation applied to all framebuffers.
+ 0 - 0 degree rotation
+ 1 - 90 degree rotation
+ 2 - 180 degree rotation
+ 3 - 270 degree rotation
+
+omapfb.mirror=<y|n>
+ - Default mirror for all framebuffers. Only works with DMA rotation.
+
+omapdss.def_disp=<display>
+ - Name of default display, to which all overlays will be connected.
+ Common examples are "lcd" or "tv".
+
+omapdss.debug=<y|n>
+ - Enable debug printing. You have to have DSS debug support enabled in
+ kernel config.
+
+TODO
+----
+
+DSS locking
+
+Error checking
+- Lots of checks are missing or implemented just as BUG()
+
+System DMA update for DSI
+- Can be used for RGB16 and RGB24P modes. Probably not for RGB24U (how
+ to skip the empty byte?)
+
+OMAP1 support
+- Not sure if needed
+
diff --git a/Documentation/arm/OMAP/omap_pm b/Documentation/arm/OMAP/omap_pm
new file mode 100644
index 00000000..9012bb03
--- /dev/null
+++ b/Documentation/arm/OMAP/omap_pm
@@ -0,0 +1,154 @@
+
+The OMAP PM interface
+=====================
+
+This document describes the temporary OMAP PM interface. Driver
+authors use these functions to communicate minimum latency or
+throughput constraints to the kernel power management code.
+Over time, the intention is to merge features from the OMAP PM
+interface into the Linux PM QoS code.
+
+Drivers need to express PM parameters which:
+
+- support the range of power management parameters present in the TI SRF;
+
+- separate the drivers from the underlying PM parameter
+ implementation, whether it is the TI SRF or Linux PM QoS or Linux
+ latency framework or something else;
+
+- specify PM parameters in terms of fundamental units, such as
+ latency and throughput, rather than units which are specific to OMAP
+ or to particular OMAP variants;
+
+- allow drivers which are shared with other architectures (e.g.,
+ DaVinci) to add these constraints in a way which won't affect non-OMAP
+ systems,
+
+- can be implemented immediately with minimal disruption of other
+ architectures.
+
+
+This document proposes the OMAP PM interface, including the following
+five power management functions for driver code:
+
+1. Set the maximum MPU wakeup latency:
+ (*pdata->set_max_mpu_wakeup_lat)(struct device *dev, unsigned long t)
+
+2. Set the maximum device wakeup latency:
+ (*pdata->set_max_dev_wakeup_lat)(struct device *dev, unsigned long t)
+
+3. Set the maximum system DMA transfer start latency (CORE pwrdm):
+ (*pdata->set_max_sdma_lat)(struct device *dev, long t)
+
+4. Set the minimum bus throughput needed by a device:
+ (*pdata->set_min_bus_tput)(struct device *dev, u8 agent_id, unsigned long r)
+
+5. Return the number of times the device has lost context
+ (*pdata->get_dev_context_loss_count)(struct device *dev)
+
+
+Further documentation for all OMAP PM interface functions can be
+found in arch/arm/plat-omap/include/mach/omap-pm.h.
+
+
+The OMAP PM layer is intended to be temporary
+---------------------------------------------
+
+The intention is that eventually the Linux PM QoS layer should support
+the range of power management features present in OMAP3. As this
+happens, existing drivers using the OMAP PM interface can be modified
+to use the Linux PM QoS code; and the OMAP PM interface can disappear.
+
+
+Driver usage of the OMAP PM functions
+-------------------------------------
+
+As the 'pdata' in the above examples indicates, these functions are
+exposed to drivers through function pointers in driver .platform_data
+structures. The function pointers are initialized by the board-*.c
+files to point to the corresponding OMAP PM functions:
+.set_max_dev_wakeup_lat will point to
+omap_pm_set_max_dev_wakeup_lat(), etc. Other architectures which do
+not support these functions should leave these function pointers set
+to NULL. Drivers should use the following idiom:
+
+ if (pdata->set_max_dev_wakeup_lat)
+ (*pdata->set_max_dev_wakeup_lat)(dev, t);
+
+The most common usage of these functions will probably be to specify
+the maximum time from when an interrupt occurs, to when the device
+becomes accessible. To accomplish this, driver writers should use the
+set_max_mpu_wakeup_lat() function to to constrain the MPU wakeup
+latency, and the set_max_dev_wakeup_lat() function to constrain the
+device wakeup latency (from clk_enable() to accessibility). For
+example,
+
+ /* Limit MPU wakeup latency */
+ if (pdata->set_max_mpu_wakeup_lat)
+ (*pdata->set_max_mpu_wakeup_lat)(dev, tc);
+
+ /* Limit device powerdomain wakeup latency */
+ if (pdata->set_max_dev_wakeup_lat)
+ (*pdata->set_max_dev_wakeup_lat)(dev, td);
+
+ /* total wakeup latency in this example: (tc + td) */
+
+The PM parameters can be overwritten by calling the function again
+with the new value. The settings can be removed by calling the
+function with a t argument of -1 (except in the case of
+set_max_bus_tput(), which should be called with an r argument of 0).
+
+The fifth function above, omap_pm_get_dev_context_loss_count(),
+is intended as an optimization to allow drivers to determine whether the
+device has lost its internal context. If context has been lost, the
+driver must restore its internal context before proceeding.
+
+
+Other specialized interface functions
+-------------------------------------
+
+The five functions listed above are intended to be usable by any
+device driver. DSPBridge and CPUFreq have a few special requirements.
+DSPBridge expresses target DSP performance levels in terms of OPP IDs.
+CPUFreq expresses target MPU performance levels in terms of MPU
+frequency. The OMAP PM interface contains functions for these
+specialized cases to convert that input information (OPPs/MPU
+frequency) into the form that the underlying power management
+implementation needs:
+
+6. (*pdata->dsp_get_opp_table)(void)
+
+7. (*pdata->dsp_set_min_opp)(u8 opp_id)
+
+8. (*pdata->dsp_get_opp)(void)
+
+9. (*pdata->cpu_get_freq_table)(void)
+
+10. (*pdata->cpu_set_freq)(unsigned long f)
+
+11. (*pdata->cpu_get_freq)(void)
+
+Customizing OPP for platform
+============================
+Defining CONFIG_PM should enable OPP layer for the silicon
+and the registration of OPP table should take place automatically.
+However, in special cases, the default OPP table may need to be
+tweaked, for e.g.:
+ * enable default OPPs which are disabled by default, but which
+ could be enabled on a platform
+ * Disable an unsupported OPP on the platform
+ * Define and add a custom opp table entry
+in these cases, the board file needs to do additional steps as follows:
+arch/arm/mach-omapx/board-xyz.c
+ #include "pm.h"
+ ....
+ static void __init omap_xyz_init_irq(void)
+ {
+ ....
+ /* Initialize the default table */
+ omapx_opp_init();
+ /* Do customization to the defaults */
+ ....
+ }
+NOTE: omapx_opp_init will be omap3_opp_init or as required
+based on the omap family.
diff --git a/Documentation/arm/Porting b/Documentation/arm/Porting
new file mode 100644
index 00000000..a4922339
--- /dev/null
+++ b/Documentation/arm/Porting
@@ -0,0 +1,135 @@
+Taken from list archive at http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2001-July/004064.html
+
+Initial definitions
+-------------------
+
+The following symbol definitions rely on you knowing the translation that
+__virt_to_phys() does for your machine. This macro converts the passed
+virtual address to a physical address. Normally, it is simply:
+
+ phys = virt - PAGE_OFFSET + PHYS_OFFSET
+
+
+Decompressor Symbols
+--------------------
+
+ZTEXTADDR
+ Start address of decompressor. There's no point in talking about
+ virtual or physical addresses here, since the MMU will be off at
+ the time when you call the decompressor code. You normally call
+ the kernel at this address to start it booting. This doesn't have
+ to be located in RAM, it can be in flash or other read-only or
+ read-write addressable medium.
+
+ZBSSADDR
+ Start address of zero-initialised work area for the decompressor.
+ This must be pointing at RAM. The decompressor will zero initialise
+ this for you. Again, the MMU will be off.
+
+ZRELADDR
+ This is the address where the decompressed kernel will be written,
+ and eventually executed. The following constraint must be valid:
+
+ __virt_to_phys(TEXTADDR) == ZRELADDR
+
+ The initial part of the kernel is carefully coded to be position
+ independent.
+
+INITRD_PHYS
+ Physical address to place the initial RAM disk. Only relevant if
+ you are using the bootpImage stuff (which only works on the old
+ struct param_struct).
+
+INITRD_VIRT
+ Virtual address of the initial RAM disk. The following constraint
+ must be valid:
+
+ __virt_to_phys(INITRD_VIRT) == INITRD_PHYS
+
+PARAMS_PHYS
+ Physical address of the struct param_struct or tag list, giving the
+ kernel various parameters about its execution environment.
+
+
+Kernel Symbols
+--------------
+
+PHYS_OFFSET
+ Physical start address of the first bank of RAM.
+
+PAGE_OFFSET
+ Virtual start address of the first bank of RAM. During the kernel
+ boot phase, virtual address PAGE_OFFSET will be mapped to physical
+ address PHYS_OFFSET, along with any other mappings you supply.
+ This should be the same value as TASK_SIZE.
+
+TASK_SIZE
+ The maximum size of a user process in bytes. Since user space
+ always starts at zero, this is the maximum address that a user
+ process can access+1. The user space stack grows down from this
+ address.
+
+ Any virtual address below TASK_SIZE is deemed to be user process
+ area, and therefore managed dynamically on a process by process
+ basis by the kernel. I'll call this the user segment.
+
+ Anything above TASK_SIZE is common to all processes. I'll call
+ this the kernel segment.
+
+ (In other words, you can't put IO mappings below TASK_SIZE, and
+ hence PAGE_OFFSET).
+
+TEXTADDR
+ Virtual start address of kernel, normally PAGE_OFFSET + 0x8000.
+ This is where the kernel image ends up. With the latest kernels,
+ it must be located at 32768 bytes into a 128MB region. Previous
+ kernels placed a restriction of 256MB here.
+
+DATAADDR
+ Virtual address for the kernel data segment. Must not be defined
+ when using the decompressor.
+
+VMALLOC_START
+VMALLOC_END
+ Virtual addresses bounding the vmalloc() area. There must not be
+ any static mappings in this area; vmalloc will overwrite them.
+ The addresses must also be in the kernel segment (see above).
+ Normally, the vmalloc() area starts VMALLOC_OFFSET bytes above the
+ last virtual RAM address (found using variable high_memory).
+
+VMALLOC_OFFSET
+ Offset normally incorporated into VMALLOC_START to provide a hole
+ between virtual RAM and the vmalloc area. We do this to allow
+ out of bounds memory accesses (eg, something writing off the end
+ of the mapped memory map) to be caught. Normally set to 8MB.
+
+Architecture Specific Macros
+----------------------------
+
+BOOT_MEM(pram,pio,vio)
+ `pram' specifies the physical start address of RAM. Must always
+ be present, and should be the same as PHYS_OFFSET.
+
+ `pio' is the physical address of an 8MB region containing IO for
+ use with the debugging macros in arch/arm/kernel/debug-armv.S.
+
+ `vio' is the virtual address of the 8MB debugging region.
+
+ It is expected that the debugging region will be re-initialised
+ by the architecture specific code later in the code (via the
+ MAPIO function).
+
+BOOT_PARAMS
+ Same as, and see PARAMS_PHYS.
+
+FIXUP(func)
+ Machine specific fixups, run before memory subsystems have been
+ initialised.
+
+MAPIO(func)
+ Machine specific function to map IO areas (including the debug
+ region above).
+
+INITIRQ(func)
+ Machine specific function to initialise interrupts.
+
diff --git a/Documentation/arm/README b/Documentation/arm/README
new file mode 100644
index 00000000..aea34095
--- /dev/null
+++ b/Documentation/arm/README
@@ -0,0 +1,197 @@
+ ARM Linux 2.6
+ =============
+
+ Please check <ftp://ftp.arm.linux.org.uk/pub/armlinux> for
+ updates.
+
+Compilation of kernel
+---------------------
+
+ In order to compile ARM Linux, you will need a compiler capable of
+ generating ARM ELF code with GNU extensions. GCC 3.3 is known to be
+ a good compiler. Fortunately, you needn't guess. The kernel will report
+ an error if your compiler is a recognized offender.
+
+ To build ARM Linux natively, you shouldn't have to alter the ARCH = line
+ in the top level Makefile. However, if you don't have the ARM Linux ELF
+ tools installed as default, then you should change the CROSS_COMPILE
+ line as detailed below.
+
+ If you wish to cross-compile, then alter the following lines in the top
+ level make file:
+
+ ARCH = <whatever>
+ with
+ ARCH = arm
+
+ and
+
+ CROSS_COMPILE=
+ to
+ CROSS_COMPILE=<your-path-to-your-compiler-without-gcc>
+ eg.
+ CROSS_COMPILE=arm-linux-
+
+ Do a 'make config', followed by 'make Image' to build the kernel
+ (arch/arm/boot/Image). A compressed image can be built by doing a
+ 'make zImage' instead of 'make Image'.
+
+
+Bug reports etc
+---------------
+
+ Please send patches to the patch system. For more information, see
+ http://www.arm.linux.org.uk/developer/patches/info.php Always include some
+ explanation as to what the patch does and why it is needed.
+
+ Bug reports should be sent to linux-arm-kernel@lists.arm.linux.org.uk,
+ or submitted through the web form at
+ http://www.arm.linux.org.uk/developer/
+
+ When sending bug reports, please ensure that they contain all relevant
+ information, eg. the kernel messages that were printed before/during
+ the problem, what you were doing, etc.
+
+
+Include files
+-------------
+
+ Several new include directories have been created under include/asm-arm,
+ which are there to reduce the clutter in the top-level directory. These
+ directories, and their purpose is listed below:
+
+ arch-* machine/platform specific header files
+ hardware driver-internal ARM specific data structures/definitions
+ mach descriptions of generic ARM to specific machine interfaces
+ proc-* processor dependent header files (currently only two
+ categories)
+
+
+Machine/Platform support
+------------------------
+
+ The ARM tree contains support for a lot of different machine types. To
+ continue supporting these differences, it has become necessary to split
+ machine-specific parts by directory. For this, the machine category is
+ used to select which directories and files get included (we will use
+ $(MACHINE) to refer to the category)
+
+ To this end, we now have arch/arm/mach-$(MACHINE) directories which are
+ designed to house the non-driver files for a particular machine (eg, PCI,
+ memory management, architecture definitions etc). For all future
+ machines, there should be a corresponding arch/arm/mach-$(MACHINE)/include/mach
+ directory.
+
+
+Modules
+-------
+
+ Although modularisation is supported (and required for the FP emulator),
+ each module on an ARM2/ARM250/ARM3 machine when is loaded will take
+ memory up to the next 32k boundary due to the size of the pages.
+ Therefore, is modularisation on these machines really worth it?
+
+ However, ARM6 and up machines allow modules to take multiples of 4k, and
+ as such Acorn RiscPCs and other architectures using these processors can
+ make good use of modularisation.
+
+
+ADFS Image files
+----------------
+
+ You can access image files on your ADFS partitions by mounting the ADFS
+ partition, and then using the loopback device driver. You must have
+ losetup installed.
+
+ Please note that the PCEmulator DOS partitions have a partition table at
+ the start, and as such, you will have to give '-o offset' to losetup.
+
+
+Request to developers
+---------------------
+
+ When writing device drivers which include a separate assembler file, please
+ include it in with the C file, and not the arch/arm/lib directory. This
+ allows the driver to be compiled as a loadable module without requiring
+ half the code to be compiled into the kernel image.
+
+ In general, try to avoid using assembler unless it is really necessary. It
+ makes drivers far less easy to port to other hardware.
+
+
+ST506 hard drives
+-----------------
+
+ The ST506 hard drive controllers seem to be working fine (if a little
+ slowly). At the moment they will only work off the controllers on an
+ A4x0's motherboard, but for it to work off a Podule just requires
+ someone with a podule to add the addresses for the IRQ mask and the
+ HDC base to the source.
+
+ As of 31/3/96 it works with two drives (you should get the ADFS
+ *configure harddrive set to 2). I've got an internal 20MB and a great
+ big external 5.25" FH 64MB drive (who could ever want more :-) ).
+
+ I've just got 240K/s off it (a dd with bs=128k); thats about half of what
+ RiscOS gets; but it's a heck of a lot better than the 50K/s I was getting
+ last week :-)
+
+ Known bug: Drive data errors can cause a hang; including cases where
+ the controller has fixed the error using ECC. (Possibly ONLY
+ in that case...hmm).
+
+
+1772 Floppy
+-----------
+ This also seems to work OK, but hasn't been stressed much lately. It
+ hasn't got any code for disc change detection in there at the moment which
+ could be a bit of a problem! Suggestions on the correct way to do this
+ are welcome.
+
+
+CONFIG_MACH_ and CONFIG_ARCH_
+-----------------------------
+ A change was made in 2003 to the macro names for new machines.
+ Historically, CONFIG_ARCH_ was used for the bonafide architecture,
+ e.g. SA1100, as well as implementations of the architecture,
+ e.g. Assabet. It was decided to change the implementation macros
+ to read CONFIG_MACH_ for clarity. Moreover, a retroactive fixup has
+ not been made because it would complicate patching.
+
+ Previous registrations may be found online.
+
+ <http://www.arm.linux.org.uk/developer/machines/>
+
+Kernel entry (head.S)
+--------------------------
+ The initial entry into the kernel is via head.S, which uses machine
+ independent code. The machine is selected by the value of 'r1' on
+ entry, which must be kept unique.
+
+ Due to the large number of machines which the ARM port of Linux provides
+ for, we have a method to manage this which ensures that we don't end up
+ duplicating large amounts of code.
+
+ We group machine (or platform) support code into machine classes. A
+ class typically based around one or more system on a chip devices, and
+ acts as a natural container around the actual implementations. These
+ classes are given directories - arch/arm/mach-<class> and
+ arch/arm/mach-<class> - which contain the source files to/include/mach
+ support the machine class. This directories also contain any machine
+ specific supporting code.
+
+ For example, the SA1100 class is based upon the SA1100 and SA1110 SoC
+ devices, and contains the code to support the way the on-board and off-
+ board devices are used, or the device is setup, and provides that
+ machine specific "personality."
+
+ This fine-grained machine specific selection is controlled by the machine
+ type ID, which acts both as a run-time and a compile-time code selection
+ method.
+
+ You can register a new machine via the web site at:
+
+ <http://www.arm.linux.org.uk/developer/machines/>
+
+---
+Russell King (15/03/2004)
diff --git a/Documentation/arm/SA1100/ADSBitsy b/Documentation/arm/SA1100/ADSBitsy
new file mode 100644
index 00000000..f9f62e8c
--- /dev/null
+++ b/Documentation/arm/SA1100/ADSBitsy
@@ -0,0 +1,43 @@
+ADS Bitsy Single Board Computer
+(It is different from Bitsy(iPAQ) of Compaq)
+
+For more details, contact Applied Data Systems or see
+http://www.applieddata.net/products.html
+
+The Linux support for this product has been provided by
+Woojung Huh <whuh@applieddata.net>
+
+Use 'make adsbitsy_config' before any 'make config'.
+This will set up defaults for ADS Bitsy support.
+
+The kernel zImage is linked to be loaded and executed at 0xc0400000.
+
+Linux can be used with the ADS BootLoader that ships with the
+newer rev boards. See their documentation on how to load Linux.
+
+Supported peripherals:
+- SA1100 LCD frame buffer (8/16bpp...sort of)
+- SA1111 USB Master
+- SA1100 serial port
+- pcmcia, compact flash
+- touchscreen(ucb1200)
+- console on LCD screen
+- serial ports (ttyS[0-2])
+ - ttyS0 is default for serial console
+
+To do:
+- everything else! :-)
+
+Notes:
+
+- The flash on board is divided into 3 partitions.
+ You should be careful to use flash on board.
+ Its partition is different from GraphicsClient Plus and GraphicsMaster
+
+- 16bpp mode requires a different cable than what ships with the board.
+ Contact ADS or look through the manual to wire your own. Currently,
+ if you compile with 16bit mode support and switch into a lower bpp
+ mode, the timing is off so the image is corrupted. This will be
+ fixed soon.
+
+Any contribution can be sent to nico@fluxnic.net and will be greatly welcome!
diff --git a/Documentation/arm/SA1100/Assabet b/Documentation/arm/SA1100/Assabet
new file mode 100644
index 00000000..08b885d3
--- /dev/null
+++ b/Documentation/arm/SA1100/Assabet
@@ -0,0 +1,300 @@
+The Intel Assabet (SA-1110 evaluation) board
+============================================
+
+Please see:
+http://developer.intel.com
+
+Also some notes from John G Dorsey <jd5q@andrew.cmu.edu>:
+http://www.cs.cmu.edu/~wearable/software/assabet.html
+
+
+Building the kernel
+-------------------
+
+To build the kernel with current defaults:
+
+ make assabet_config
+ make oldconfig
+ make zImage
+
+The resulting kernel image should be available in linux/arch/arm/boot/zImage.
+
+
+Installing a bootloader
+-----------------------
+
+A couple of bootloaders able to boot Linux on Assabet are available:
+
+BLOB (http://www.lartmaker.nl/lartware/blob/)
+
+ BLOB is a bootloader used within the LART project. Some contributed
+ patches were merged into BLOB to add support for Assabet.
+
+Compaq's Bootldr + John Dorsey's patch for Assabet support
+(http://www.handhelds.org/Compaq/bootldr.html)
+(http://www.wearablegroup.org/software/bootldr/)
+
+ Bootldr is the bootloader developed by Compaq for the iPAQ Pocket PC.
+ John Dorsey has produced add-on patches to add support for Assabet and
+ the JFFS filesystem.
+
+RedBoot (http://sources.redhat.com/redboot/)
+
+ RedBoot is a bootloader developed by Red Hat based on the eCos RTOS
+ hardware abstraction layer. It supports Assabet amongst many other
+ hardware platforms.
+
+RedBoot is currently the recommended choice since it's the only one to have
+networking support, and is the most actively maintained.
+
+Brief examples on how to boot Linux with RedBoot are shown below. But first
+you need to have RedBoot installed in your flash memory. A known to work
+precompiled RedBoot binary is available from the following location:
+
+ftp://ftp.netwinder.org/users/n/nico/
+ftp://ftp.arm.linux.org.uk/pub/linux/arm/people/nico/
+ftp://ftp.handhelds.org/pub/linux/arm/sa-1100-patches/
+
+Look for redboot-assabet*.tgz. Some installation infos are provided in
+redboot-assabet*.txt.
+
+
+Initial RedBoot configuration
+-----------------------------
+
+The commands used here are explained in The RedBoot User's Guide available
+on-line at http://sources.redhat.com/ecos/docs.html.
+Please refer to it for explanations.
+
+If you have a CF network card (my Assabet kit contained a CF+ LP-E from
+Socket Communications Inc.), you should strongly consider using it for TFTP
+file transfers. You must insert it before RedBoot runs since it can't detect
+it dynamically.
+
+To initialize the flash directory:
+
+ fis init -f
+
+To initialize the non-volatile settings, like whether you want to use BOOTP or
+a static IP address, etc, use this command:
+
+ fconfig -i
+
+
+Writing a kernel image into flash
+---------------------------------
+
+First, the kernel image must be loaded into RAM. If you have the zImage file
+available on a TFTP server:
+
+ load zImage -r -b 0x100000
+
+If you rather want to use Y-Modem upload over the serial port:
+
+ load -m ymodem -r -b 0x100000
+
+To write it to flash:
+
+ fis create "Linux kernel" -b 0x100000 -l 0xc0000
+
+
+Booting the kernel
+------------------
+
+The kernel still requires a filesystem to boot. A ramdisk image can be loaded
+as follows:
+
+ load ramdisk_image.gz -r -b 0x800000
+
+Again, Y-Modem upload can be used instead of TFTP by replacing the file name
+by '-y ymodem'.
+
+Now the kernel can be retrieved from flash like this:
+
+ fis load "Linux kernel"
+
+or loaded as described previously. To boot the kernel:
+
+ exec -b 0x100000 -l 0xc0000
+
+The ramdisk image could be stored into flash as well, but there are better
+solutions for on-flash filesystems as mentioned below.
+
+
+Using JFFS2
+-----------
+
+Using JFFS2 (the Second Journalling Flash File System) is probably the most
+convenient way to store a writable filesystem into flash. JFFS2 is used in
+conjunction with the MTD layer which is responsible for low-level flash
+management. More information on the Linux MTD can be found on-line at:
+http://www.linux-mtd.infradead.org/. A JFFS howto with some infos about
+creating JFFS/JFFS2 images is available from the same site.
+
+For instance, a sample JFFS2 image can be retrieved from the same FTP sites
+mentioned below for the precompiled RedBoot image.
+
+To load this file:
+
+ load sample_img.jffs2 -r -b 0x100000
+
+The result should look like:
+
+RedBoot> load sample_img.jffs2 -r -b 0x100000
+Raw file loaded 0x00100000-0x00377424
+
+Now we must know the size of the unallocated flash:
+
+ fis free
+
+Result:
+
+RedBoot> fis free
+ 0x500E0000 .. 0x503C0000
+
+The values above may be different depending on the size of the filesystem and
+the type of flash. See their usage below as an example and take care of
+substituting yours appropriately.
+
+We must determine some values:
+
+size of unallocated flash: 0x503c0000 - 0x500e0000 = 0x2e0000
+size of the filesystem image: 0x00377424 - 0x00100000 = 0x277424
+
+We want to fit the filesystem image of course, but we also want to give it all
+the remaining flash space as well. To write it:
+
+ fis unlock -f 0x500E0000 -l 0x2e0000
+ fis erase -f 0x500E0000 -l 0x2e0000
+ fis write -b 0x100000 -l 0x277424 -f 0x500E0000
+ fis create "JFFS2" -n -f 0x500E0000 -l 0x2e0000
+
+Now the filesystem is associated to a MTD "partition" once Linux has discovered
+what they are in the boot process. From Redboot, the 'fis list' command
+displays them:
+
+RedBoot> fis list
+Name FLASH addr Mem addr Length Entry point
+RedBoot 0x50000000 0x50000000 0x00020000 0x00000000
+RedBoot config 0x503C0000 0x503C0000 0x00020000 0x00000000
+FIS directory 0x503E0000 0x503E0000 0x00020000 0x00000000
+Linux kernel 0x50020000 0x00100000 0x000C0000 0x00000000
+JFFS2 0x500E0000 0x500E0000 0x002E0000 0x00000000
+
+However Linux should display something like:
+
+SA1100 flash: probing 32-bit flash bus
+SA1100 flash: Found 2 x16 devices at 0x0 in 32-bit mode
+Using RedBoot partition definition
+Creating 5 MTD partitions on "SA1100 flash":
+0x00000000-0x00020000 : "RedBoot"
+0x00020000-0x000e0000 : "Linux kernel"
+0x000e0000-0x003c0000 : "JFFS2"
+0x003c0000-0x003e0000 : "RedBoot config"
+0x003e0000-0x00400000 : "FIS directory"
+
+What's important here is the position of the partition we are interested in,
+which is the third one. Within Linux, this correspond to /dev/mtdblock2.
+Therefore to boot Linux with the kernel and its root filesystem in flash, we
+need this RedBoot command:
+
+ fis load "Linux kernel"
+ exec -b 0x100000 -l 0xc0000 -c "root=/dev/mtdblock2"
+
+Of course other filesystems than JFFS might be used, like cramfs for example.
+You might want to boot with a root filesystem over NFS, etc. It is also
+possible, and sometimes more convenient, to flash a filesystem directly from
+within Linux while booted from a ramdisk or NFS. The Linux MTD repository has
+many tools to deal with flash memory as well, to erase it for example. JFFS2
+can then be mounted directly on a freshly erased partition and files can be
+copied over directly. Etc...
+
+
+RedBoot scripting
+-----------------
+
+All the commands above aren't so useful if they have to be typed in every
+time the Assabet is rebooted. Therefore it's possible to automatize the boot
+process using RedBoot's scripting capability.
+
+For example, I use this to boot Linux with both the kernel and the ramdisk
+images retrieved from a TFTP server on the network:
+
+RedBoot> fconfig
+Run script at boot: false true
+Boot script:
+Enter script, terminate with empty line
+>> load zImage -r -b 0x100000
+>> load ramdisk_ks.gz -r -b 0x800000
+>> exec -b 0x100000 -l 0xc0000
+>>
+Boot script timeout (1000ms resolution): 3
+Use BOOTP for network configuration: true
+GDB connection port: 9000
+Network debug at boot time: false
+Update RedBoot non-volatile configuration - are you sure (y/n)? y
+
+Then, rebooting the Assabet is just a matter of waiting for the login prompt.
+
+
+
+Nicolas Pitre
+nico@fluxnic.net
+June 12, 2001
+
+
+Status of peripherals in -rmk tree (updated 14/10/2001)
+-------------------------------------------------------
+
+Assabet:
+ Serial ports:
+ Radio: TX, RX, CTS, DSR, DCD, RI
+ PM: Not tested.
+ COM: TX, RX, CTS, DSR, DCD, RTS, DTR, PM
+ PM: Not tested.
+ I2C: Implemented, not fully tested.
+ L3: Fully tested, pass.
+ PM: Not tested.
+
+ Video:
+ LCD: Fully tested. PM
+ (LCD doesn't like being blanked with
+ neponset connected)
+ Video out: Not fully
+
+ Audio:
+ UDA1341:
+ Playback: Fully tested, pass.
+ Record: Implemented, not tested.
+ PM: Not tested.
+
+ UCB1200:
+ Audio play: Implemented, not heavily tested.
+ Audio rec: Implemented, not heavily tested.
+ Telco audio play: Implemented, not heavily tested.
+ Telco audio rec: Implemented, not heavily tested.
+ POTS control: No
+ Touchscreen: Yes
+ PM: Not tested.
+
+ Other:
+ PCMCIA:
+ LPE: Fully tested, pass.
+ USB: No
+ IRDA:
+ SIR: Fully tested, pass.
+ FIR: Fully tested, pass.
+ PM: Not tested.
+
+Neponset:
+ Serial ports:
+ COM1,2: TX, RX, CTS, DSR, DCD, RTS, DTR
+ PM: Not tested.
+ USB: Implemented, not heavily tested.
+ PCMCIA: Implemented, not heavily tested.
+ PM: Not tested.
+ CF: Implemented, not heavily tested.
+ PM: Not tested.
+
+More stuff can be found in the -np (Nicolas Pitre's) tree.
+
diff --git a/Documentation/arm/SA1100/Brutus b/Documentation/arm/SA1100/Brutus
new file mode 100644
index 00000000..6a3aa95e
--- /dev/null
+++ b/Documentation/arm/SA1100/Brutus
@@ -0,0 +1,66 @@
+Brutus is an evaluation platform for the SA1100 manufactured by Intel.
+For more details, see:
+
+http://developer.intel.com
+
+To compile for Brutus, you must issue the following commands:
+
+ make brutus_config
+ make config
+ [accept all the defaults]
+ make zImage
+
+The resulting kernel will end up in linux/arch/arm/boot/zImage. This file
+must be loaded at 0xc0008000 in Brutus's memory and execution started at
+0xc0008000 as well with the value of registers r0 = 0 and r1 = 16 upon
+entry.
+
+But prior to execute the kernel, a ramdisk image must also be loaded in
+memory. Use memory address 0xd8000000 for this. Note that the file
+containing the (compressed) ramdisk image must not exceed 4 MB.
+
+Typically, you'll need angelboot to load the kernel.
+The following angelboot.opt file should be used:
+
+----- begin angelboot.opt -----
+base 0xc0008000
+entry 0xc0008000
+r0 0x00000000
+r1 0x00000010
+device /dev/ttyS0
+options "9600 8N1"
+baud 115200
+otherfile ramdisk_img.gz
+otherbase 0xd8000000
+----- end angelboot.opt -----
+
+Then load the kernel and ramdisk with:
+
+ angelboot -f angelboot.opt zImage
+
+The first Brutus serial port (assumed to be linked to /dev/ttyS0 on your
+host PC) is used by angel to load the kernel and ramdisk image. The serial
+console is provided through the second Brutus serial port. To access it,
+you may use minicom configured with /dev/ttyS1, 9600 baud, 8N1, no flow
+control.
+
+Currently supported:
+ - RS232 serial ports
+ - audio output
+ - LCD screen
+ - keyboard
+
+The actual Brutus support may not be complete without extra patches.
+If such patches exist, they should be found from
+ftp.netwinder.org/users/n/nico.
+
+A full PCMCIA support is still missing, although it's possible to hack
+some drivers in order to drive already inserted cards at boot time with
+little modifications.
+
+Any contribution is welcome.
+
+Please send patches to nico@fluxnic.net
+
+Have Fun !
+
diff --git a/Documentation/arm/SA1100/CERF b/Documentation/arm/SA1100/CERF
new file mode 100644
index 00000000..b3d84530
--- /dev/null
+++ b/Documentation/arm/SA1100/CERF
@@ -0,0 +1,29 @@
+*** The StrongARM version of the CerfBoard/Cube has been discontinued ***
+
+The Intrinsyc CerfBoard is a StrongARM 1110-based computer on a board
+that measures approximately 2" square. It includes an Ethernet
+controller, an RS232-compatible serial port, a USB function port, and
+one CompactFlash+ slot on the back. Pictures can be found at the
+Intrinsyc website, http://www.intrinsyc.com.
+
+This document describes the support in the Linux kernel for the
+Intrinsyc CerfBoard.
+
+Supported in this version:
+ - CompactFlash+ slot (select PCMCIA in General Setup and any options
+ that may be required)
+ - Onboard Crystal CS8900 Ethernet controller (Cerf CS8900A support in
+ Network Devices)
+ - Serial ports with a serial console (hardcoded to 38400 8N1)
+
+In order to get this kernel onto your Cerf, you need a server that runs
+both BOOTP and TFTP. Detailed instructions should have come with your
+evaluation kit on how to use the bootloader. This series of commands
+will suffice:
+
+ make ARCH=arm CROSS_COMPILE=arm-linux- cerfcube_defconfig
+ make ARCH=arm CROSS_COMPILE=arm-linux- zImage
+ make ARCH=arm CROSS_COMPILE=arm-linux- modules
+ cp arch/arm/boot/zImage <TFTP directory>
+
+support@intrinsyc.com
diff --git a/Documentation/arm/SA1100/FreeBird b/Documentation/arm/SA1100/FreeBird
new file mode 100644
index 00000000..ab919366
--- /dev/null
+++ b/Documentation/arm/SA1100/FreeBird
@@ -0,0 +1,21 @@
+Freebird-1.1 is produced by Legend(C), Inc.
+http://web.archive.org/web/*/http://www.legend.com.cn
+and software/linux maintained by Coventive(C), Inc.
+(http://www.coventive.com)
+
+Based on the Nicolas's strongarm kernel tree.
+
+===============================================================
+Maintainer:
+
+Chester Kuo <chester@coventive.com>
+ <chester@linux.org.tw>
+
+Author :
+Tim wu <timwu@coventive.com>
+CIH <cih@coventive.com>
+Eric Peng <ericpeng@coventive.com>
+Jeff Lee <jeff_lee@coventive.com>
+Allen Cheng
+Tony Liu <tonyliu@coventive.com>
+
diff --git a/Documentation/arm/SA1100/GraphicsClient b/Documentation/arm/SA1100/GraphicsClient
new file mode 100644
index 00000000..867bb359
--- /dev/null
+++ b/Documentation/arm/SA1100/GraphicsClient
@@ -0,0 +1,98 @@
+ADS GraphicsClient Plus Single Board Computer
+
+For more details, contact Applied Data Systems or see
+http://www.applieddata.net/products.html
+
+The original Linux support for this product has been provided by
+Nicolas Pitre <nico@fluxnic.net>. Continued development work by
+Woojung Huh <whuh@applieddata.net>
+
+It's currently possible to mount a root filesystem via NFS providing a
+complete Linux environment. Otherwise a ramdisk image may be used. The
+board supports MTD/JFFS, so you could also mount something on there.
+
+Use 'make graphicsclient_config' before any 'make config'. This will set up
+defaults for GraphicsClient Plus support.
+
+The kernel zImage is linked to be loaded and executed at 0xc0200000.
+Also the following registers should have the specified values upon entry:
+
+ r0 = 0
+ r1 = 29 (this is the GraphicsClient architecture number)
+
+Linux can be used with the ADS BootLoader that ships with the
+newer rev boards. See their documentation on how to load Linux.
+Angel is not available for the GraphicsClient Plus AFAIK.
+
+There is a board known as just the GraphicsClient that ADS used to
+produce but has end of lifed. This code will not work on the older
+board with the ADS bootloader, but should still work with Angel,
+as outlined below. In any case, if you're planning on deploying
+something en masse, you should probably get the newer board.
+
+If using Angel on the older boards, here is a typical angel.opt option file
+if the kernel is loaded through the Angel Debug Monitor:
+
+----- begin angelboot.opt -----
+base 0xc0200000
+entry 0xc0200000
+r0 0x00000000
+r1 0x0000001d
+device /dev/ttyS1
+options "38400 8N1"
+baud 115200
+#otherfile ramdisk.gz
+#otherbase 0xc0800000
+exec minicom
+----- end angelboot.opt -----
+
+Then the kernel (and ramdisk if otherfile/otherbase lines above are
+uncommented) would be loaded with:
+
+ angelboot -f angelboot.opt zImage
+
+Here it is assumed that the board is connected to ttyS1 on your PC
+and that minicom is preconfigured with /dev/ttyS1, 38400 baud, 8N1, no flow
+control by default.
+
+If any other bootloader is used, ensure it accomplish the same, especially
+for r0/r1 register values before jumping into the kernel.
+
+
+Supported peripherals:
+- SA1100 LCD frame buffer (8/16bpp...sort of)
+- on-board SMC 92C96 ethernet NIC
+- SA1100 serial port
+- flash memory access (MTD/JFFS)
+- pcmcia
+- touchscreen(ucb1200)
+- ps/2 keyboard
+- console on LCD screen
+- serial ports (ttyS[0-2])
+ - ttyS0 is default for serial console
+- Smart I/O (ADC, keypad, digital inputs, etc)
+ See http://www.eurotech-inc.com/linux-sbc.asp for IOCTL documentation
+ and example user space code. ps/2 keybd is multiplexed through this driver
+
+To do:
+- UCB1200 audio with new ucb_generic layer
+- everything else! :-)
+
+Notes:
+
+- The flash on board is divided into 3 partitions. mtd0 is where
+ the ADS boot ROM and zImage is stored. It's been marked as
+ read-only to keep you from blasting over the bootloader. :) mtd1 is
+ for the ramdisk.gz image. mtd2 is user flash space and can be
+ utilized for either JFFS or if you're feeling crazy, running ext2
+ on top of it. If you're not using the ADS bootloader, you're
+ welcome to blast over the mtd1 partition also.
+
+- 16bpp mode requires a different cable than what ships with the board.
+ Contact ADS or look through the manual to wire your own. Currently,
+ if you compile with 16bit mode support and switch into a lower bpp
+ mode, the timing is off so the image is corrupted. This will be
+ fixed soon.
+
+Any contribution can be sent to nico@fluxnic.net and will be greatly welcome!
+
diff --git a/Documentation/arm/SA1100/GraphicsMaster b/Documentation/arm/SA1100/GraphicsMaster
new file mode 100644
index 00000000..9145088a
--- /dev/null
+++ b/Documentation/arm/SA1100/GraphicsMaster
@@ -0,0 +1,53 @@
+ADS GraphicsMaster Single Board Computer
+
+For more details, contact Applied Data Systems or see
+http://www.applieddata.net/products.html
+
+The original Linux support for this product has been provided by
+Nicolas Pitre <nico@fluxnic.net>. Continued development work by
+Woojung Huh <whuh@applieddata.net>
+
+Use 'make graphicsmaster_config' before any 'make config'.
+This will set up defaults for GraphicsMaster support.
+
+The kernel zImage is linked to be loaded and executed at 0xc0400000.
+
+Linux can be used with the ADS BootLoader that ships with the
+newer rev boards. See their documentation on how to load Linux.
+
+Supported peripherals:
+- SA1100 LCD frame buffer (8/16bpp...sort of)
+- SA1111 USB Master
+- on-board SMC 92C96 ethernet NIC
+- SA1100 serial port
+- flash memory access (MTD/JFFS)
+- pcmcia, compact flash
+- touchscreen(ucb1200)
+- ps/2 keyboard
+- console on LCD screen
+- serial ports (ttyS[0-2])
+ - ttyS0 is default for serial console
+- Smart I/O (ADC, keypad, digital inputs, etc)
+ See http://www.eurotech-inc.com/linux-sbc.asp for IOCTL documentation
+ and example user space code. ps/2 keybd is multiplexed through this driver
+
+To do:
+- everything else! :-)
+
+Notes:
+
+- The flash on board is divided into 3 partitions. mtd0 is where
+ the zImage is stored. It's been marked as read-only to keep you
+ from blasting over the bootloader. :) mtd1 is
+ for the ramdisk.gz image. mtd2 is user flash space and can be
+ utilized for either JFFS or if you're feeling crazy, running ext2
+ on top of it. If you're not using the ADS bootloader, you're
+ welcome to blast over the mtd1 partition also.
+
+- 16bpp mode requires a different cable than what ships with the board.
+ Contact ADS or look through the manual to wire your own. Currently,
+ if you compile with 16bit mode support and switch into a lower bpp
+ mode, the timing is off so the image is corrupted. This will be
+ fixed soon.
+
+Any contribution can be sent to nico@fluxnic.net and will be greatly welcome!
diff --git a/Documentation/arm/SA1100/HUW_WEBPANEL b/Documentation/arm/SA1100/HUW_WEBPANEL
new file mode 100644
index 00000000..fd56b48d
--- /dev/null
+++ b/Documentation/arm/SA1100/HUW_WEBPANEL
@@ -0,0 +1,17 @@
+The HUW_WEBPANEL is a product of the german company Hoeft & Wessel AG
+
+If you want more information, please visit
+http://www.hoeft-wessel.de
+
+To build the kernel:
+ make huw_webpanel_config
+ make oldconfig
+ [accept all defaults]
+ make zImage
+
+Mostly of the work is done by:
+Roman Jordan jor@hoeft-wessel.de
+Christoph Schulz schu@hoeft-wessel.de
+
+2000/12/18/
+
diff --git a/Documentation/arm/SA1100/Itsy b/Documentation/arm/SA1100/Itsy
new file mode 100644
index 00000000..44b94997
--- /dev/null
+++ b/Documentation/arm/SA1100/Itsy
@@ -0,0 +1,39 @@
+Itsy is a research project done by the Western Research Lab, and Systems
+Research Center in Palo Alto, CA. The Itsy project is one of several
+research projects at Compaq that are related to pocket computing.
+
+For more information, see:
+
+ http://www.hpl.hp.com/downloads/crl/itsy/
+
+Notes on initial 2.4 Itsy support (8/27/2000) :
+The port was done on an Itsy version 1.5 machine with a daughtercard with
+64 Meg of DRAM and 32 Meg of Flash. The initial work includes support for
+serial console (to see what you're doing). No other devices have been
+enabled.
+
+To build, do a "make menuconfig" (or xmenuconfig) and select Itsy support.
+Disable Flash and LCD support. and then do a make zImage.
+Finally, you will need to cd to arch/arm/boot/tools and execute a make there
+to build the params-itsy program used to boot the kernel.
+
+In order to install the port of 2.4 to the itsy, You will need to set the
+configuration parameters in the monitor as follows:
+Arg 1:0x08340000, Arg2: 0xC0000000, Arg3:18 (0x12), Arg4:0
+Make sure the start-routine address is set to 0x00060000.
+
+Next, flash the params-itsy program to 0x00060000 ("p 1 0x00060000" in the
+flash menu) Flash the kernel in arch/arm/boot/zImage into 0x08340000
+("p 1 0x00340000"). Finally flash an initial ramdisk into 0xC8000000
+("p 2 0x0") We used ramdisk-2-30.gz from the 0.11 version directory on
+handhelds.org.
+
+The serial connection we established was at:
+ 8-bit data, no parity, 1 stop bit(s), 115200.00 b/s. in the monitor, in the
+params-itsy program, and in the kernel itself. This can be changed, but
+not easily. The monitor parameters are easily changed, the params program
+setup is assembly outl's, and the kernel is a configuration item specific to
+the itsy. (i.e. grep for CONFIG_SA1100_ITSY and you'll find where it is.)
+
+
+This should get you a properly booting 2.4 kernel on the itsy.
diff --git a/Documentation/arm/SA1100/LART b/Documentation/arm/SA1100/LART
new file mode 100644
index 00000000..6d412b68
--- /dev/null
+++ b/Documentation/arm/SA1100/LART
@@ -0,0 +1,14 @@
+Linux Advanced Radio Terminal (LART)
+------------------------------------
+
+The LART is a small (7.5 x 10cm) SA-1100 board, designed for embedded
+applications. It has 32 MB DRAM, 4MB Flash ROM, double RS232 and all
+other StrongARM-gadgets. Almost all SA signals are directly accessible
+through a number of connectors. The powersupply accepts voltages
+between 3.5V and 16V and is overdimensioned to support a range of
+daughterboards. A quad Ethernet / IDE / PS2 / sound daughterboard
+is under development, with plenty of others in different stages of
+planning.
+
+The hardware designs for this board have been released under an open license;
+see the LART page at http://www.lartmaker.nl/ for more information.
diff --git a/Documentation/arm/SA1100/PLEB b/Documentation/arm/SA1100/PLEB
new file mode 100644
index 00000000..b9c8a631
--- /dev/null
+++ b/Documentation/arm/SA1100/PLEB
@@ -0,0 +1,11 @@
+The PLEB project was started as a student initiative at the School of
+Computer Science and Engineering, University of New South Wales to make a
+pocket computer capable of running the Linux Kernel.
+
+PLEB support has yet to be fully integrated.
+
+For more information, see:
+
+ http://www.cse.unsw.edu.au
+
+
diff --git a/Documentation/arm/SA1100/Pangolin b/Documentation/arm/SA1100/Pangolin
new file mode 100644
index 00000000..077a6120
--- /dev/null
+++ b/Documentation/arm/SA1100/Pangolin
@@ -0,0 +1,23 @@
+Pangolin is a StrongARM 1110-based evaluation platform produced
+by Dialogue Technology (http://www.dialogue.com.tw/).
+It has EISA slots for ease of configuration with SDRAM/Flash
+memory card, USB/Serial/Audio card, Compact Flash card,
+PCMCIA/IDE card and TFT-LCD card.
+
+To compile for Pangolin, you must issue the following commands:
+
+ make pangolin_config
+ make oldconfig
+ make zImage
+
+Supported peripherals:
+- SA1110 serial port (UART1/UART2/UART3)
+- flash memory access
+- compact flash driver
+- UDA1341 sound driver
+- SA1100 LCD controller for 800x600 16bpp TFT-LCD
+- MQ-200 driver for 800x600 16bpp TFT-LCD
+- Penmount(touch panel) driver
+- PCMCIA driver
+- SMC91C94 LAN driver
+- IDE driver (experimental)
diff --git a/Documentation/arm/SA1100/Tifon b/Documentation/arm/SA1100/Tifon
new file mode 100644
index 00000000..dd1934d9
--- /dev/null
+++ b/Documentation/arm/SA1100/Tifon
@@ -0,0 +1,7 @@
+Tifon
+-----
+
+More info has to come...
+
+Contact: Peter Danielsson <peter.danielsson@era-t.ericsson.se>
+
diff --git a/Documentation/arm/SA1100/Victor b/Documentation/arm/SA1100/Victor
new file mode 100644
index 00000000..9cff415d
--- /dev/null
+++ b/Documentation/arm/SA1100/Victor
@@ -0,0 +1,16 @@
+Victor is known as a "digital talking book player" manufactured by
+VisuAide, Inc. to be used by blind people.
+
+For more information related to Victor, see:
+
+ http://www.humanware.com/en-usa/products
+
+Of course Victor is using Linux as its main operating system.
+The Victor implementation for Linux is maintained by Nicolas Pitre:
+
+ nico@visuaide.com
+ nico@fluxnic.net
+
+For any comments, please feel free to contact me through the above
+addresses.
+
diff --git a/Documentation/arm/SA1100/Yopy b/Documentation/arm/SA1100/Yopy
new file mode 100644
index 00000000..e14f16d8
--- /dev/null
+++ b/Documentation/arm/SA1100/Yopy
@@ -0,0 +1,2 @@
+See http://www.yopydeveloper.org for more.
+
diff --git a/Documentation/arm/SA1100/empeg b/Documentation/arm/SA1100/empeg
new file mode 100644
index 00000000..4ece4849
--- /dev/null
+++ b/Documentation/arm/SA1100/empeg
@@ -0,0 +1,2 @@
+See ../empeg/README
+
diff --git a/Documentation/arm/SA1100/nanoEngine b/Documentation/arm/SA1100/nanoEngine
new file mode 100644
index 00000000..48a7934f
--- /dev/null
+++ b/Documentation/arm/SA1100/nanoEngine
@@ -0,0 +1,11 @@
+nanoEngine
+----------
+
+"nanoEngine" is a SA1110 based single board computer from
+Bright Star Engineering Inc. See www.brightstareng.com/arm
+for more info.
+(Ref: Stuart Adams <sja@brightstareng.com>)
+
+Also visit Larry Doolittle's "Linux for the nanoEngine" site:
+http://www.brightstareng.com/arm/nanoeng.htm
+
diff --git a/Documentation/arm/SA1100/serial_UART b/Documentation/arm/SA1100/serial_UART
new file mode 100644
index 00000000..a63966f1
--- /dev/null
+++ b/Documentation/arm/SA1100/serial_UART
@@ -0,0 +1,47 @@
+The SA1100 serial port had its major/minor numbers officially assigned:
+
+> Date: Sun, 24 Sep 2000 21:40:27 -0700
+> From: H. Peter Anvin <hpa@transmeta.com>
+> To: Nicolas Pitre <nico@CAM.ORG>
+> Cc: Device List Maintainer <device@lanana.org>
+> Subject: Re: device
+>
+> Okay. Note that device numbers 204 and 205 are used for "low density
+> serial devices", so you will have a range of minors on those majors (the
+> tty device layer handles this just fine, so you don't have to worry about
+> doing anything special.)
+>
+> So your assignments are:
+>
+> 204 char Low-density serial ports
+> 5 = /dev/ttySA0 SA1100 builtin serial port 0
+> 6 = /dev/ttySA1 SA1100 builtin serial port 1
+> 7 = /dev/ttySA2 SA1100 builtin serial port 2
+>
+> 205 char Low-density serial ports (alternate device)
+> 5 = /dev/cusa0 Callout device for ttySA0
+> 6 = /dev/cusa1 Callout device for ttySA1
+> 7 = /dev/cusa2 Callout device for ttySA2
+>
+
+You must create those inodes in /dev on the root filesystem used
+by your SA1100-based device:
+
+ mknod ttySA0 c 204 5
+ mknod ttySA1 c 204 6
+ mknod ttySA2 c 204 7
+ mknod cusa0 c 205 5
+ mknod cusa1 c 205 6
+ mknod cusa2 c 205 7
+
+In addition to the creation of the appropriate device nodes above, you
+must ensure your user space applications make use of the correct device
+name. The classic example is the content of the /etc/inittab file where
+you might have a getty process started on ttyS0. In this case:
+
+- replace occurrences of ttyS0 with ttySA0, ttyS1 with ttySA1, etc.
+
+- don't forget to add 'ttySA0', 'console', or the appropriate tty name
+ in /etc/securetty for root to be allowed to login as well.
+
+
diff --git a/Documentation/arm/SH-Mobile/Makefile b/Documentation/arm/SH-Mobile/Makefile
new file mode 100644
index 00000000..8771d832
--- /dev/null
+++ b/Documentation/arm/SH-Mobile/Makefile
@@ -0,0 +1,8 @@
+BIN := vrl4
+
+.PHONY: all
+all: $(BIN)
+
+.PHONY: clean
+clean:
+ rm -f *.o $(BIN)
diff --git a/Documentation/arm/SH-Mobile/vrl4.c b/Documentation/arm/SH-Mobile/vrl4.c
new file mode 100644
index 00000000..e8a19135
--- /dev/null
+++ b/Documentation/arm/SH-Mobile/vrl4.c
@@ -0,0 +1,169 @@
+/*
+ * vrl4 format generator
+ *
+ * Copyright (C) 2010 Simon Horman
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+/*
+ * usage: vrl4 < zImage > out
+ * dd if=out of=/dev/sdx bs=512 seek=1 # Write the image to sector 1
+ *
+ * Reads a zImage from stdin and writes a vrl4 image to stdout.
+ * In practice this means writing a padded vrl4 header to stdout followed
+ * by the zImage.
+ *
+ * The padding places the zImage at ALIGN bytes into the output.
+ * The vrl4 uses ALIGN + START_BASE as the start_address.
+ * This is where the mask ROM will jump to after verifying the header.
+ *
+ * The header sets copy_size to min(sizeof(zImage), MAX_BOOT_PROG_LEN) + ALIGN.
+ * That is, the mask ROM will load the padded header (ALIGN bytes)
+ * And then MAX_BOOT_PROG_LEN bytes of the image, or the entire image,
+ * whichever is smaller.
+ *
+ * The zImage is not modified in any way.
+ */
+
+#define _BSD_SOURCE
+#include <endian.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <errno.h>
+
+struct hdr {
+ uint32_t magic1;
+ uint32_t reserved1;
+ uint32_t magic2;
+ uint32_t reserved2;
+ uint16_t copy_size;
+ uint16_t boot_options;
+ uint32_t reserved3;
+ uint32_t start_address;
+ uint32_t reserved4;
+ uint32_t reserved5;
+ char reserved6[308];
+};
+
+#define DECLARE_HDR(h) \
+ struct hdr (h) = { \
+ .magic1 = htole32(0xea000000), \
+ .reserved1 = htole32(0x56), \
+ .magic2 = htole32(0xe59ff008), \
+ .reserved3 = htole16(0x1) }
+
+/* Align to 512 bytes, the MMCIF sector size */
+#define ALIGN_BITS 9
+#define ALIGN (1 << ALIGN_BITS)
+
+#define START_BASE 0xe55b0000
+
+/*
+ * With an alignment of 512 the header uses the first sector.
+ * There is a 128 sector (64kbyte) limit on the data loaded by the mask ROM.
+ * So there are 127 sectors left for the boot programme. But in practice
+ * Only a small portion of a zImage is needed, 16 sectors should be more
+ * than enough.
+ *
+ * Note that this sets how much of the zImage is copied by the mask ROM.
+ * The entire zImage is present after the header and is loaded
+ * by the code in the boot program (which is the first portion of the zImage).
+ */
+#define MAX_BOOT_PROG_LEN (16 * 512)
+
+#define ROUND_UP(x) ((x + ALIGN - 1) & ~(ALIGN - 1))
+
+ssize_t do_read(int fd, void *buf, size_t count)
+{
+ size_t offset = 0;
+ ssize_t l;
+
+ while (offset < count) {
+ l = read(fd, buf + offset, count - offset);
+ if (!l)
+ break;
+ if (l < 0) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ continue;
+ perror("read");
+ return -1;
+ }
+ offset += l;
+ }
+
+ return offset;
+}
+
+ssize_t do_write(int fd, const void *buf, size_t count)
+{
+ size_t offset = 0;
+ ssize_t l;
+
+ while (offset < count) {
+ l = write(fd, buf + offset, count - offset);
+ if (l < 0) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ continue;
+ perror("write");
+ return -1;
+ }
+ offset += l;
+ }
+
+ return offset;
+}
+
+ssize_t write_zero(int fd, size_t len)
+{
+ size_t i = len;
+
+ while (i--) {
+ const char x = 0;
+ if (do_write(fd, &x, 1) < 0)
+ return -1;
+ }
+
+ return len;
+}
+
+int main(void)
+{
+ DECLARE_HDR(hdr);
+ char boot_program[MAX_BOOT_PROG_LEN];
+ size_t aligned_hdr_len, alligned_prog_len;
+ ssize_t prog_len;
+
+ prog_len = do_read(0, boot_program, sizeof(boot_program));
+ if (prog_len <= 0)
+ return -1;
+
+ aligned_hdr_len = ROUND_UP(sizeof(hdr));
+ hdr.start_address = htole32(START_BASE + aligned_hdr_len);
+ alligned_prog_len = ROUND_UP(prog_len);
+ hdr.copy_size = htole16(aligned_hdr_len + alligned_prog_len);
+
+ if (do_write(1, &hdr, sizeof(hdr)) < 0)
+ return -1;
+ if (write_zero(1, aligned_hdr_len - sizeof(hdr)) < 0)
+ return -1;
+
+ if (do_write(1, boot_program, prog_len) < 0)
+ return 1;
+
+ /* Write out the rest of the kernel */
+ while (1) {
+ prog_len = do_read(0, boot_program, sizeof(boot_program));
+ if (prog_len < 0)
+ return 1;
+ if (prog_len == 0)
+ break;
+ if (do_write(1, boot_program, prog_len) < 0)
+ return 1;
+ }
+
+ return 0;
+}
diff --git a/Documentation/arm/SH-Mobile/zboot-rom-mmcif.txt b/Documentation/arm/SH-Mobile/zboot-rom-mmcif.txt
new file mode 100644
index 00000000..efff8ae2
--- /dev/null
+++ b/Documentation/arm/SH-Mobile/zboot-rom-mmcif.txt
@@ -0,0 +1,29 @@
+ROM-able zImage boot from MMC
+-----------------------------
+
+An ROM-able zImage compiled with ZBOOT_ROM_MMCIF may be written to MMC and
+SuperH Mobile ARM will to boot directly from the MMCIF hardware block.
+
+This is achieved by the mask ROM loading the first portion of the image into
+MERAM and then jumping to it. This portion contains loader code which
+copies the entire image to SDRAM and jumps to it. From there the zImage
+boot code proceeds as normal, uncompressing the image into its final
+location and then jumping to it.
+
+This code has been tested on an AP4EB board using the developer 1A eMMC
+boot mode which is configured using the following jumper settings.
+The board used for testing required a patched mask ROM in order for
+this mode to function.
+
+ 8 7 6 5 4 3 2 1
+ x|x|x|x|x| |x|
+S4 -+-+-+-+-+-+-+-
+ | | | | |x| |x on
+
+The zImage must be written to the MMC card at sector 1 (512 bytes) in
+vrl4 format. A utility vrl4 is supplied to accomplish this.
+
+e.g.
+ vrl4 < zImage | dd of=/dev/sdX bs=512 seek=1
+
+A dual-voltage MMC 4.0 card was used for testing.
diff --git a/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt
new file mode 100644
index 00000000..44195984
--- /dev/null
+++ b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt
@@ -0,0 +1,42 @@
+ROM-able zImage boot from eSD
+-----------------------------
+
+An ROM-able zImage compiled with ZBOOT_ROM_SDHI may be written to eSD and
+SuperH Mobile ARM will to boot directly from the SDHI hardware block.
+
+This is achieved by the mask ROM loading the first portion of the image into
+MERAM and then jumping to it. This portion contains loader code which
+copies the entire image to SDRAM and jumps to it. From there the zImage
+boot code proceeds as normal, uncompressing the image into its final
+location and then jumping to it.
+
+This code has been tested on an mackerel board using the developer 1A eSD
+boot mode which is configured using the following jumper settings.
+
+ 8 7 6 5 4 3 2 1
+ x|x|x|x| |x|x|
+S4 -+-+-+-+-+-+-+-
+ | | | |x| | |x on
+
+The eSD card needs to be present in SDHI slot 1 (CN7).
+As such S1 and S33 also need to be configured as per
+the notes in arch/arm/mach-shmobile/board-mackerel.c.
+
+A partial zImage must be written to physical partition #1 (boot)
+of the eSD at sector 0 in vrl4 format. A utility vrl4 is supplied to
+accomplish this.
+
+e.g.
+ vrl4 < zImage | dd of=/dev/sdX bs=512 count=17
+
+A full copy of _the same_ zImage should be written to physical partition #1
+(boot) of the eSD at sector 0. This should _not_ be in vrl4 format.
+
+ vrl4 < zImage | dd of=/dev/sdX bs=512
+
+Note: The commands above assume that the physical partition has been
+switched. No such facility currently exists in the Linux Kernel.
+
+Physical partitions are described in the eSD specification. At the time of
+writing they are not the same as partitions that are typically configured
+using fdisk and visible through /proc/partitions
diff --git a/Documentation/arm/SPEAr/overview.txt b/Documentation/arm/SPEAr/overview.txt
new file mode 100644
index 00000000..65610bf5
--- /dev/null
+++ b/Documentation/arm/SPEAr/overview.txt
@@ -0,0 +1,63 @@
+ SPEAr ARM Linux Overview
+ ==========================
+
+Introduction
+------------
+
+ SPEAr (Structured Processor Enhanced Architecture).
+ weblink : http://www.st.com/spear
+
+ The ST Microelectronics SPEAr range of ARM9/CortexA9 System-on-Chip CPUs are
+ supported by the 'spear' platform of ARM Linux. Currently SPEAr1310,
+ SPEAr1340, SPEAr300, SPEAr310, SPEAr320 and SPEAr600 SOCs are supported.
+
+ Hierarchy in SPEAr is as follows:
+
+ SPEAr (Platform)
+ - SPEAr3XX (3XX SOC series, based on ARM9)
+ - SPEAr300 (SOC)
+ - SPEAr300 Evaluation Board
+ - SPEAr310 (SOC)
+ - SPEAr310 Evaluation Board
+ - SPEAr320 (SOC)
+ - SPEAr320 Evaluation Board
+ - SPEAr6XX (6XX SOC series, based on ARM9)
+ - SPEAr600 (SOC)
+ - SPEAr600 Evaluation Board
+ - SPEAr13XX (13XX SOC series, based on ARM CORTEXA9)
+ - SPEAr1310 (SOC)
+ - SPEAr1310 Evaluation Board
+ - SPEAr1340 (SOC)
+ - SPEAr1340 Evaluation Board
+
+ Configuration
+ -------------
+
+ A generic configuration is provided for each machine, and can be used as the
+ default by
+ make spear13xx_defconfig
+ make spear3xx_defconfig
+ make spear6xx_defconfig
+
+ Layout
+ ------
+
+ The common files for multiple machine families (SPEAr3xx, SPEAr6xx and
+ SPEAr13xx) are located in the platform code contained in arch/arm/plat-spear
+ with headers in plat/.
+
+ Each machine series have a directory with name arch/arm/mach-spear followed by
+ series name. Like mach-spear3xx, mach-spear6xx and mach-spear13xx.
+
+ Common file for machines of spear3xx family is mach-spear3xx/spear3xx.c, for
+ spear6xx is mach-spear6xx/spear6xx.c and for spear13xx family is
+ mach-spear13xx/spear13xx.c. mach-spear* also contain soc/machine specific
+ files, like spear1310.c, spear1340.c spear300.c, spear310.c, spear320.c and
+ spear600.c. mach-spear* doesn't contains board specific files as they fully
+ support Flattened Device Tree.
+
+
+ Document Author
+ ---------------
+
+ Viresh Kumar <viresh.linux@gmail.com>, (c) 2010-2012 ST Microelectronics
diff --git a/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt b/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt
new file mode 100644
index 00000000..fa968aa9
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt
@@ -0,0 +1,75 @@
+ S3C24XX CPUfreq support
+ =======================
+
+Introduction
+------------
+
+ The S3C24XX series support a number of power saving systems, such as
+ the ability to change the core, memory and peripheral operating
+ frequencies. The core control is exported via the CPUFreq driver
+ which has a number of different manual or automatic controls over the
+ rate the core is running at.
+
+ There are two forms of the driver depending on the specific CPU and
+ how the clocks are arranged. The first implementation used as single
+ PLL to feed the ARM, memory and peripherals via a series of dividers
+ and muxes and this is the implementation that is documented here. A
+ newer version where there is a separate PLL and clock divider for the
+ ARM core is available as a separate driver.
+
+
+Layout
+------
+
+ The code core manages the CPU specific drivers, any data that they
+ need to register and the interface to the generic drivers/cpufreq
+ system. Each CPU registers a driver to control the PLL, clock dividers
+ and anything else associated with it. Any board that wants to use this
+ framework needs to supply at least basic details of what is required.
+
+ The core registers with drivers/cpufreq at init time if all the data
+ necessary has been supplied.
+
+
+CPU support
+-----------
+
+ The support for each CPU depends on the facilities provided by the
+ SoC and the driver as each device has different PLL and clock chains
+ associated with it.
+
+
+Slow Mode
+---------
+
+ The SLOW mode where the PLL is turned off altogether and the
+ system is fed by the external crystal input is currently not
+ supported.
+
+
+sysfs
+-----
+
+ The core code exports extra information via sysfs in the directory
+ devices/system/cpu/cpu0/arch-freq.
+
+
+Board Support
+-------------
+
+ Each board that wants to use the cpufreq code must register some basic
+ information with the core driver to provide information about what the
+ board requires and any restrictions being placed on it.
+
+ The board needs to supply information about whether it needs the IO bank
+ timings changing, any maximum frequency limits and information about the
+ SDRAM refresh rate.
+
+
+
+
+Document Author
+---------------
+
+Ben Dooks, Copyright 2009 Simtec Electronics
+Licensed under GPLv2
diff --git a/Documentation/arm/Samsung-S3C24XX/DMA.txt b/Documentation/arm/Samsung-S3C24XX/DMA.txt
new file mode 100644
index 00000000..3ed82383
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/DMA.txt
@@ -0,0 +1,46 @@
+ S3C2410 DMA
+ ===========
+
+Introduction
+------------
+
+ The kernel provides an interface to manage DMA transfers
+ using the DMA channels in the CPU, so that the central
+ duty of managing channel mappings, and programming the
+ channel generators is in one place.
+
+
+DMA Channel Ordering
+--------------------
+
+ Many of the range do not have connections for the DMA
+ channels to all sources, which means that some devices
+ have a restricted number of channels that can be used.
+
+ To allow flexibility for each CPU type and board, the
+ DMA code can be given a DMA ordering structure which
+ allows the order of channel search to be specified, as
+ well as allowing the prohibition of certain claims.
+
+ struct s3c24xx_dma_order has a list of channels, and
+ each channel within has a slot for a list of DMA
+ channel numbers. The slots are searched in order for
+ the presence of a DMA channel number with DMA_CH_VALID
+ or-ed in.
+
+ If the order has the flag DMA_CH_NEVER set, then after
+ checking the channel list, the system will return no
+ found channel, thus denying the request.
+
+ A board support file can call s3c24xx_dma_order_set()
+ to register a complete ordering set. The routine will
+ copy the data, so the original can be discarded with
+ __initdata.
+
+
+Authour
+-------
+
+Ben Dooks,
+Copyright (c) 2007 Ben Dooks, Simtec Electronics
+Licensed under the GPL v2
diff --git a/Documentation/arm/Samsung-S3C24XX/EB2410ITX.txt b/Documentation/arm/Samsung-S3C24XX/EB2410ITX.txt
new file mode 100644
index 00000000..b87292e0
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/EB2410ITX.txt
@@ -0,0 +1,58 @@
+ Simtec Electronics EB2410ITX (BAST)
+ ===================================
+
+ http://www.simtec.co.uk/products/EB2410ITX/
+
+Introduction
+------------
+
+ The EB2410ITX is a S3C2410 based development board with a variety of
+ peripherals and expansion connectors. This board is also known by
+ the shortened name of Bast.
+
+
+Configuration
+-------------
+
+ To set the default configuration, use `make bast_defconfig` which
+ supports the commonly used features of this board.
+
+
+Support
+-------
+
+ Official support information can be found on the Simtec Electronics
+ website, at the product page http://www.simtec.co.uk/products/EB2410ITX/
+
+ Useful links:
+
+ - Resources Page http://www.simtec.co.uk/products/EB2410ITX/resources.html
+
+ - Board FAQ at http://www.simtec.co.uk/products/EB2410ITX/faq.html
+
+ - Bootloader info http://www.simtec.co.uk/products/SWABLE/resources.html
+ and FAQ http://www.simtec.co.uk/products/SWABLE/faq.html
+
+
+MTD
+---
+
+ The NAND and NOR support has been merged from the linux-mtd project.
+ Any problems, see http://www.linux-mtd.infradead.org/ for more
+ information or up-to-date versions of linux-mtd.
+
+
+IDE
+---
+
+ Both onboard IDE ports are supported, however there is no support for
+ changing speed of devices, PIO Mode 4 capable drives should be used.
+
+
+Maintainers
+-----------
+
+ This board is maintained by Simtec Electronics.
+
+
+Copyright 2004 Ben Dooks, Simtec Electronics
diff --git a/Documentation/arm/Samsung-S3C24XX/GPIO.txt b/Documentation/arm/Samsung-S3C24XX/GPIO.txt
new file mode 100644
index 00000000..8b46c796
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/GPIO.txt
@@ -0,0 +1,182 @@
+ S3C24XX GPIO Control
+ ====================
+
+Introduction
+------------
+
+ The s3c2410 kernel provides an interface to configure and
+ manipulate the state of the GPIO pins, and find out other
+ information about them.
+
+ There are a number of conditions attached to the configuration
+ of the s3c2410 GPIO system, please read the Samsung provided
+ data-sheet/users manual to find out the complete list.
+
+ See Documentation/arm/Samsung/GPIO.txt for the core implementation.
+
+
+GPIOLIB
+-------
+
+ With the event of the GPIOLIB in drivers/gpio, support for some
+ of the GPIO functions such as reading and writing a pin will
+ be removed in favour of this common access method.
+
+ Once all the extant drivers have been converted, the functions
+ listed below will be removed (they may be marked as __deprecated
+ in the near future).
+
+ The following functions now either have a s3c_ specific variant
+ or are merged into gpiolib. See the definitions in
+ arch/arm/plat-samsung/include/plat/gpio-cfg.h:
+
+ s3c2410_gpio_setpin() gpio_set_value() or gpio_direction_output()
+ s3c2410_gpio_getpin() gpio_get_value() or gpio_direction_input()
+ s3c2410_gpio_getirq() gpio_to_irq()
+ s3c2410_gpio_cfgpin() s3c_gpio_cfgpin()
+ s3c2410_gpio_getcfg() s3c_gpio_getcfg()
+ s3c2410_gpio_pullup() s3c_gpio_setpull()
+
+
+GPIOLIB conversion
+------------------
+
+If you need to convert your board or driver to use gpiolib from the phased
+out s3c2410 API, then here are some notes on the process.
+
+1) If your board is exclusively using an GPIO, say to control peripheral
+ power, then it will require to claim the gpio with gpio_request() before
+ it can use it.
+
+ It is recommended to check the return value, with at least WARN_ON()
+ during initialisation.
+
+2) The s3c2410_gpio_cfgpin() can be directly replaced with s3c_gpio_cfgpin()
+ as they have the same arguments, and can either take the pin specific
+ values, or the more generic special-function-number arguments.
+
+3) s3c2410_gpio_pullup() changes have the problem that whilst the
+ s3c2410_gpio_pullup(x, 1) can be easily translated to the
+ s3c_gpio_setpull(x, S3C_GPIO_PULL_NONE), the s3c2410_gpio_pullup(x, 0)
+ are not so easy.
+
+ The s3c2410_gpio_pullup(x, 0) case enables the pull-up (or in the case
+ of some of the devices, a pull-down) and as such the new API distinguishes
+ between the UP and DOWN case. There is currently no 'just turn on' setting
+ which may be required if this becomes a problem.
+
+4) s3c2410_gpio_setpin() can be replaced by gpio_set_value(), the old call
+ does not implicitly configure the relevant gpio to output. The gpio
+ direction should be changed before using gpio_set_value().
+
+5) s3c2410_gpio_getpin() is replaceable by gpio_get_value() if the pin
+ has been set to input. It is currently unknown what the behaviour is
+ when using gpio_get_value() on an output pin (s3c2410_gpio_getpin
+ would return the value the pin is supposed to be outputting).
+
+6) s3c2410_gpio_getirq() should be directly replaceable with the
+ gpio_to_irq() call.
+
+The s3c2410_gpio and gpio_ calls have always operated on the same gpio
+numberspace, so there is no problem with converting the gpio numbering
+between the calls.
+
+
+Headers
+-------
+
+ See arch/arm/mach-s3c2410/include/mach/regs-gpio.h for the list
+ of GPIO pins, and the configuration values for them. This
+ is included by using #include <mach/regs-gpio.h>
+
+ The GPIO management functions are defined in the hardware
+ header arch/arm/mach-s3c2410/include/mach/hardware.h which can be
+ included by #include <mach/hardware.h>
+
+ A useful amount of documentation can be found in the hardware
+ header on how the GPIO functions (and others) work.
+
+ Whilst a number of these functions do make some checks on what
+ is passed to them, for speed of use, they may not always ensure
+ that the user supplied data to them is correct.
+
+
+PIN Numbers
+-----------
+
+ Each pin has an unique number associated with it in regs-gpio.h,
+ e.g. S3C2410_GPA(0) or S3C2410_GPF(1). These defines are used to tell
+ the GPIO functions which pin is to be used.
+
+ With the conversion to gpiolib, there is no longer a direct conversion
+ from gpio pin number to register base address as in earlier kernels. This
+ is due to the number space required for newer SoCs where the later
+ GPIOs are not contiguous.
+
+
+Configuring a pin
+-----------------
+
+ The following function allows the configuration of a given pin to
+ be changed.
+
+ void s3c_gpio_cfgpin(unsigned int pin, unsigned int function);
+
+ e.g.:
+
+ s3c_gpio_cfgpin(S3C2410_GPA(0), S3C_GPIO_SFN(1));
+ s3c_gpio_cfgpin(S3C2410_GPE(8), S3C_GPIO_SFN(2));
+
+ which would turn GPA(0) into the lowest Address line A0, and set
+ GPE(8) to be connected to the SDIO/MMC controller's SDDAT1 line.
+
+
+Reading the current configuration
+---------------------------------
+
+ The current configuration of a pin can be read by using standard
+ gpiolib function:
+
+ s3c_gpio_getcfg(unsigned int pin);
+
+ The return value will be from the same set of values which can be
+ passed to s3c_gpio_cfgpin().
+
+
+Configuring a pull-up resistor
+------------------------------
+
+ A large proportion of the GPIO pins on the S3C2410 can have weak
+ pull-up resistors enabled. This can be configured by the following
+ function:
+
+ void s3c_gpio_setpull(unsigned int pin, unsigned int to);
+
+ Where the to value is S3C_GPIO_PULL_NONE to set the pull-up off,
+ and S3C_GPIO_PULL_UP to enable the specified pull-up. Any other
+ values are currently undefined.
+
+
+Getting and setting the state of a PIN
+--------------------------------------
+
+ These calls are now implemented by the relevant gpiolib calls, convert
+ your board or driver to use gpiolib.
+
+
+Getting the IRQ number associated with a PIN
+--------------------------------------------
+
+ A standard gpiolib function can map the given pin number to an IRQ
+ number to pass to the IRQ system.
+
+ int gpio_to_irq(unsigned int pin);
+
+ Note, not all pins have an IRQ.
+
+
+Author
+-------
+
+Ben Dooks, 03 October 2004
+Copyright 2004 Ben Dooks, Simtec Electronics
diff --git a/Documentation/arm/Samsung-S3C24XX/H1940.txt b/Documentation/arm/Samsung-S3C24XX/H1940.txt
new file mode 100644
index 00000000..b738859b
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/H1940.txt
@@ -0,0 +1,40 @@
+ HP IPAQ H1940
+ =============
+
+http://www.handhelds.org/projects/h1940.html
+
+Introduction
+------------
+
+ The HP H1940 is a S3C2410 based handheld device, with
+ bluetooth connectivity.
+
+
+Support
+-------
+
+ A variety of information is available
+
+ handhelds.org project page:
+
+ http://www.handhelds.org/projects/h1940.html
+
+ handhelds.org wiki page:
+
+ http://handhelds.org/moin/moin.cgi/HpIpaqH1940
+
+ Herbert Pötzl pages:
+
+ http://vserver.13thfloor.at/H1940/
+
+
+Maintainers
+-----------
+
+ This project is being maintained and developed by a variety
+ of people, including Ben Dooks, Arnaud Patard, and Herbert Pötzl.
+
+ Thanks to the many others who have also provided support.
+
+
+(c) 2005 Ben Dooks
diff --git a/Documentation/arm/Samsung-S3C24XX/NAND.txt b/Documentation/arm/Samsung-S3C24XX/NAND.txt
new file mode 100644
index 00000000..bc478a34
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/NAND.txt
@@ -0,0 +1,30 @@
+ S3C24XX NAND Support
+ ====================
+
+Introduction
+------------
+
+Small Page NAND
+---------------
+
+The driver uses a 512 byte (1 page) ECC code for this setup. The
+ECC code is not directly compatible with the default kernel ECC
+code, so the driver enforces its own OOB layout and ECC parameters
+
+Large Page NAND
+---------------
+
+The driver is capable of handling NAND flash with a 2KiB page
+size, with support for hardware ECC generation and correction.
+
+Unlike the 512byte page mode, the driver generates ECC data for
+each 256 byte block in an 2KiB page. This means that more than
+one error in a page can be rectified. It also means that the
+OOB layout remains the default kernel layout for these flashes.
+
+
+Document Author
+---------------
+
+Ben Dooks, Copyright 2007 Simtec Electronics
+
diff --git a/Documentation/arm/Samsung-S3C24XX/Overview.txt b/Documentation/arm/Samsung-S3C24XX/Overview.txt
new file mode 100644
index 00000000..359587b2
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/Overview.txt
@@ -0,0 +1,318 @@
+ S3C24XX ARM Linux Overview
+ ==========================
+
+
+
+Introduction
+------------
+
+ The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported
+ by the 's3c2410' architecture of ARM Linux. Currently the S3C2410,
+ S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443 and S3C2450 devices
+ are supported.
+
+ Support for the S3C2400 and S3C24A0 series was never completed and the
+ corresponding code has been removed after a while. If someone wishes to
+ revive this effort, partial support can be retrieved from earlier Linux
+ versions.
+
+ The S3C2416 and S3C2450 devices are very similar and S3C2450 support is
+ included under the arch/arm/mach-s3c2416 directory. Note, whilst core
+ support for these SoCs is in, work on some of the extra peripherals
+ and extra interrupts is still ongoing.
+
+
+Configuration
+-------------
+
+ A generic S3C2410 configuration is provided, and can be used as the
+ default by `make s3c2410_defconfig`. This configuration has support
+ for all the machines, and the commonly used features on them.
+
+ Certain machines may have their own default configurations as well,
+ please check the machine specific documentation.
+
+
+Layout
+------
+
+ The core support files are located in the platform code contained in
+ arch/arm/plat-s3c24xx with headers in include/asm-arm/plat-s3c24xx.
+ This directory should be kept to items shared between the platform
+ code (arch/arm/plat-s3c24xx) and the arch/arm/mach-s3c24* code.
+
+ Each cpu has a directory with the support files for it, and the
+ machines that carry the device. For example S3C2410 is contained
+ in arch/arm/mach-s3c2410 and S3C2440 in arch/arm/mach-s3c2440
+
+ Register, kernel and platform data definitions are held in the
+ arch/arm/mach-s3c2410 directory./include/mach
+
+arch/arm/plat-s3c24xx:
+
+ Files in here are either common to all the s3c24xx family,
+ or are common to only some of them with names to indicate this
+ status. The files that are not common to all are generally named
+ with the initial cpu they support in the series to ensure a short
+ name without any possibility of confusion with newer devices.
+
+ As an example, initially s3c244x would cover s3c2440 and s3c2442, but
+ with the s3c2443 which does not share many of the same drivers in
+ this directory, the name becomes invalid. We stick to s3c2440-<x>
+ to indicate a driver that is s3c2440 and s3c2442 compatible.
+
+ This does mean that to find the status of any given SoC, a number
+ of directories may need to be searched.
+
+
+Machines
+--------
+
+ The currently supported machines are as follows:
+
+ Simtec Electronics EB2410ITX (BAST)
+
+ A general purpose development board, see EB2410ITX.txt for further
+ details
+
+ Simtec Electronics IM2440D20 (Osiris)
+
+ CPU Module from Simtec Electronics, with a S3C2440A CPU, nand flash
+ and a PCMCIA controller.
+
+ Samsung SMDK2410
+
+ Samsung's own development board, geared for PDA work.
+
+ Samsung/Aiji SMDK2412
+
+ The S3C2412 version of the SMDK2440.
+
+ Samsung/Aiji SMDK2413
+
+ The S3C2412 version of the SMDK2440.
+
+ Samsung/Meritech SMDK2440
+
+ The S3C2440 compatible version of the SMDK2440, which has the
+ option of an S3C2440 or S3C2442 CPU module.
+
+ Thorcom VR1000
+
+ Custom embedded board
+
+ HP IPAQ 1940
+
+ Handheld (IPAQ), available in several varieties
+
+ HP iPAQ rx3715
+
+ S3C2440 based IPAQ, with a number of variations depending on
+ features shipped.
+
+ Acer N30
+
+ A S3C2410 based PDA from Acer. There is a Wiki page at
+ http://handhelds.org/moin/moin.cgi/AcerN30Documentation .
+
+ AML M5900
+
+ American Microsystems' M5900
+
+ Nex Vision Nexcoder
+ Nex Vision Otom
+
+ Two machines by Nex Vision
+
+
+Adding New Machines
+-------------------
+
+ The architecture has been designed to support as many machines as can
+ be configured for it in one kernel build, and any future additions
+ should keep this in mind before altering items outside of their own
+ machine files.
+
+ Machine definitions should be kept in linux/arch/arm/mach-s3c2410,
+ and there are a number of examples that can be looked at.
+
+ Read the kernel patch submission policies as well as the
+ Documentation/arm directory before submitting patches. The
+ ARM kernel series is managed by Russell King, and has a patch system
+ located at http://www.arm.linux.org.uk/developer/patches/
+ as well as mailing lists that can be found from the same site.
+
+ As a courtesy, please notify <ben-linux@fluff.org> of any new
+ machines or other modifications.
+
+ Any large scale modifications, or new drivers should be discussed
+ on the ARM kernel mailing list (linux-arm-kernel) before being
+ attempted. See http://www.arm.linux.org.uk/mailinglists/ for the
+ mailing list information.
+
+
+I2C
+---
+
+ The hardware I2C core in the CPU is supported in single master
+ mode, and can be configured via platform data.
+
+
+RTC
+---
+
+ Support for the onboard RTC unit, including alarm function.
+
+ This has recently been upgraded to use the new RTC core,
+ and the module has been renamed to rtc-s3c to fit in with
+ the new rtc naming scheme.
+
+
+Watchdog
+--------
+
+ The onchip watchdog is available via the standard watchdog
+ interface.
+
+
+NAND
+----
+
+ The current kernels now have support for the s3c2410 NAND
+ controller. If there are any problems the latest linux-mtd
+ code can be found from http://www.linux-mtd.infradead.org/
+
+ For more information see Documentation/arm/Samsung-S3C24XX/NAND.txt
+
+
+SD/MMC
+------
+
+ The SD/MMC hardware pre S3C2443 is supported in the current
+ kernel, the driver is drivers/mmc/host/s3cmci.c and supports
+ 1 and 4 bit SD or MMC cards.
+
+ The SDIO behaviour of this driver has not been fully tested. There is no
+ current support for hardware SDIO interrupts.
+
+
+Serial
+------
+
+ The s3c2410 serial driver provides support for the internal
+ serial ports. These devices appear as /dev/ttySAC0 through 3.
+
+ To create device nodes for these, use the following commands
+
+ mknod ttySAC0 c 204 64
+ mknod ttySAC1 c 204 65
+ mknod ttySAC2 c 204 66
+
+
+GPIO
+----
+
+ The core contains support for manipulating the GPIO, see the
+ documentation in GPIO.txt in the same directory as this file.
+
+ Newer kernels carry GPIOLIB, and support is being moved towards
+ this with some of the older support in line to be removed.
+
+ As of v2.6.34, the move towards using gpiolib support is almost
+ complete, and very little of the old calls are left.
+
+ See Documentation/arm/Samsung-S3C24XX/GPIO.txt for the S3C24XX specific
+ support and Documentation/arm/Samsung/GPIO.txt for the core Samsung
+ implementation.
+
+
+Clock Management
+----------------
+
+ The core provides the interface defined in the header file
+ include/asm-arm/hardware/clock.h, to allow control over the
+ various clock units
+
+
+Suspend to RAM
+--------------
+
+ For boards that provide support for suspend to RAM, the
+ system can be placed into low power suspend.
+
+ See Suspend.txt for more information.
+
+
+SPI
+---
+
+ SPI drivers are available for both the in-built hardware
+ (although there is no DMA support yet) and a generic
+ GPIO based solution.
+
+
+LEDs
+----
+
+ There is support for GPIO based LEDs via a platform driver
+ in the LED subsystem.
+
+
+Platform Data
+-------------
+
+ Whenever a device has platform specific data that is specified
+ on a per-machine basis, care should be taken to ensure the
+ following:
+
+ 1) that default data is not left in the device to confuse the
+ driver if a machine does not set it at startup
+
+ 2) the data should (if possible) be marked as __initdata,
+ to ensure that the data is thrown away if the machine is
+ not the one currently in use.
+
+ The best way of doing this is to make a function that
+ kmalloc()s an area of memory, and copies the __initdata
+ and then sets the relevant device's platform data. Making
+ the function `__init` takes care of ensuring it is discarded
+ with the rest of the initialisation code
+
+ static __init void s3c24xx_xxx_set_platdata(struct xxx_data *pd)
+ {
+ struct s3c2410_xxx_mach_info *npd;
+
+ npd = kmalloc(sizeof(struct s3c2410_xxx_mach_info), GFP_KERNEL);
+ if (npd) {
+ memcpy(npd, pd, sizeof(struct s3c2410_xxx_mach_info));
+ s3c_device_xxx.dev.platform_data = npd;
+ } else {
+ printk(KERN_ERR "no memory for xxx platform data\n");
+ }
+ }
+
+ Note, since the code is marked as __init, it should not be
+ exported outside arch/arm/mach-s3c2410/, or exported to
+ modules via EXPORT_SYMBOL() and related functions.
+
+
+Port Contributors
+-----------------
+
+ Ben Dooks (BJD)
+ Vincent Sanders
+ Herbert Potzl
+ Arnaud Patard (RTP)
+ Roc Wu
+ Klaus Fetscher
+ Dimitry Andric
+ Shannon Holland
+ Guillaume Gourat (NexVision)
+ Christer Weinigel (wingel) (Acer N30)
+ Lucas Correia Villa Real (S3C2400 port)
+
+
+Document Author
+---------------
+
+Ben Dooks, Copyright 2004-2006 Simtec Electronics
diff --git a/Documentation/arm/Samsung-S3C24XX/S3C2412.txt b/Documentation/arm/Samsung-S3C24XX/S3C2412.txt
new file mode 100644
index 00000000..f057876b
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/S3C2412.txt
@@ -0,0 +1,120 @@
+ S3C2412 ARM Linux Overview
+ ==========================
+
+Introduction
+------------
+
+ The S3C2412 is part of the S3C24XX range of ARM9 System-on-Chip CPUs
+ from Samsung. This part has an ARM926-EJS core, capable of running up
+ to 266MHz (see data-sheet for more information)
+
+
+Clock
+-----
+
+ The core clock code provides a set of clocks to the drivers, and allows
+ for source selection and a number of other features.
+
+
+Power
+-----
+
+ No support for suspend/resume to RAM in the current system.
+
+
+DMA
+---
+
+ No current support for DMA.
+
+
+GPIO
+----
+
+ There is support for setting the GPIO to input/output/special function
+ and reading or writing to them.
+
+
+UART
+----
+
+ The UART hardware is similar to the S3C2440, and is supported by the
+ s3c2410 driver in the drivers/serial directory.
+
+
+NAND
+----
+
+ The NAND hardware is similar to the S3C2440, and is supported by the
+ s3c2410 driver in the drivers/mtd/nand directory.
+
+
+USB Host
+--------
+
+ The USB hardware is similar to the S3C2410, with extended clock source
+ control. The OHCI portion is supported by the ohci-s3c2410 driver, and
+ the clock control selection is supported by the core clock code.
+
+
+USB Device
+----------
+
+ No current support in the kernel
+
+
+IRQs
+----
+
+ All the standard, and external interrupt sources are supported. The
+ extra sub-sources are not yet supported.
+
+
+RTC
+---
+
+ The RTC hardware is similar to the S3C2410, and is supported by the
+ s3c2410-rtc driver.
+
+
+Watchdog
+--------
+
+ The watchdog hardware is the same as the S3C2410, and is supported by
+ the s3c2410_wdt driver.
+
+
+MMC/SD/SDIO
+-----------
+
+ No current support for the MMC/SD/SDIO block.
+
+IIC
+---
+
+ The IIC hardware is the same as the S3C2410, and is supported by the
+ i2c-s3c24xx driver.
+
+
+IIS
+---
+
+ No current support for the IIS interface.
+
+
+SPI
+---
+
+ No current support for the SPI interfaces.
+
+
+ATA
+---
+
+ No current support for the on-board ATA block.
+
+
+Document Author
+---------------
+
+Ben Dooks, Copyright 2006 Simtec Electronics
diff --git a/Documentation/arm/Samsung-S3C24XX/S3C2413.txt b/Documentation/arm/Samsung-S3C24XX/S3C2413.txt
new file mode 100644
index 00000000..909bdc7d
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/S3C2413.txt
@@ -0,0 +1,21 @@
+ S3C2413 ARM Linux Overview
+ ==========================
+
+Introduction
+------------
+
+ The S3C2413 is an extended version of the S3C2412, with an camera
+ interface and mobile DDR memory support. See the S3C2412 support
+ documentation for more information.
+
+
+Camera Interface
+---------------
+
+ This block is currently not supported.
+
+
+Document Author
+---------------
+
+Ben Dooks, Copyright 2006 Simtec Electronics
diff --git a/Documentation/arm/Samsung-S3C24XX/SMDK2440.txt b/Documentation/arm/Samsung-S3C24XX/SMDK2440.txt
new file mode 100644
index 00000000..429390bd
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/SMDK2440.txt
@@ -0,0 +1,56 @@
+ Samsung/Meritech SMDK2440
+ =========================
+
+Introduction
+------------
+
+ The SMDK2440 is a two part evaluation board for the Samsung S3C2440
+ processor. It includes support for LCD, SmartMedia, Audio, SD and
+ 10MBit Ethernet, and expansion headers for various signals, including
+ the camera and unused GPIO.
+
+
+Configuration
+-------------
+
+ To set the default configuration, use `make smdk2440_defconfig` which
+ will configure the common features of this board, or use
+ `make s3c2410_config` to include support for all s3c2410/s3c2440 machines
+
+
+Support
+-------
+
+ Ben Dooks' SMDK2440 site at http://www.fluff.org/ben/smdk2440/ which
+ includes linux based USB download tools.
+
+ Some of the h1940 patches that can be found from the H1940 project
+ site at http://www.handhelds.org/projects/h1940.html can also be
+ applied to this board.
+
+
+Peripherals
+-----------
+
+ There is no current support for any of the extra peripherals on the
+ base-board itself.
+
+
+MTD
+---
+
+ The NAND flash should be supported by the in kernel MTD NAND support,
+ NOR flash will be added later.
+
+
+Maintainers
+-----------
+
+ This board is being maintained by Ben Dooks, for more info, see
+ http://www.fluff.org/ben/smdk2440/
+
+ Many thanks to Dimitry Andric of TomTom for the loan of the SMDK2440,
+ and to Simtec Electronics for allowing me time to work on this.
+
+
+(c) 2004 Ben Dooks
diff --git a/Documentation/arm/Samsung-S3C24XX/Suspend.txt b/Documentation/arm/Samsung-S3C24XX/Suspend.txt
new file mode 100644
index 00000000..1ca63b3e
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/Suspend.txt
@@ -0,0 +1,137 @@
+ S3C24XX Suspend Support
+ =======================
+
+
+Introduction
+------------
+
+ The S3C24XX supports a low-power suspend mode, where the SDRAM is kept
+ in Self-Refresh mode, and all but the essential peripheral blocks are
+ powered down. For more information on how this works, please look
+ at the relevant CPU datasheet from Samsung.
+
+
+Requirements
+------------
+
+ 1) A bootloader that can support the necessary resume operation
+
+ 2) Support for at least 1 source for resume
+
+ 3) CONFIG_PM enabled in the kernel
+
+ 4) Any peripherals that are going to be powered down at the same
+ time require suspend/resume support.
+
+
+Resuming
+--------
+
+ The S3C2410 user manual defines the process of sending the CPU to
+ sleep and how it resumes. The default behaviour of the Linux code
+ is to set the GSTATUS3 register to the physical address of the
+ code to resume Linux operation.
+
+ GSTATUS4 is currently left alone by the sleep code, and is free to
+ use for any other purposes (for example, the EB2410ITX uses this to
+ save memory configuration in).
+
+
+Machine Support
+---------------
+
+ The machine specific functions must call the s3c_pm_init() function
+ to say that its bootloader is capable of resuming. This can be as
+ simple as adding the following to the machine's definition:
+
+ INITMACHINE(s3c_pm_init)
+
+ A board can do its own setup before calling s3c_pm_init, if it
+ needs to setup anything else for power management support.
+
+ There is currently no support for over-riding the default method of
+ saving the resume address, if your board requires it, then contact
+ the maintainer and discuss what is required.
+
+ Note, the original method of adding an late_initcall() is wrong,
+ and will end up initialising all compiled machines' pm init!
+
+ The following is an example of code used for testing wakeup from
+ an falling edge on IRQ_EINT0:
+
+
+static irqreturn_t button_irq(int irq, void *pw)
+{
+ return IRQ_HANDLED;
+}
+
+statuc void __init machine_init(void)
+{
+ ...
+
+ request_irq(IRQ_EINT0, button_irq, IRQF_TRIGGER_FALLING,
+ "button-irq-eint0", NULL);
+
+ enable_irq_wake(IRQ_EINT0);
+
+ s3c_pm_init();
+}
+
+
+Debugging
+---------
+
+ There are several important things to remember when using PM suspend:
+
+ 1) The uart drivers will disable the clocks to the UART blocks when
+ suspending, which means that use of printascii() or similar direct
+ access to the UARTs will cause the debug to stop.
+
+ 2) Whilst the pm code itself will attempt to re-enable the UART clocks,
+ care should be taken that any external clock sources that the UARTs
+ rely on are still enabled at that point.
+
+ 3) If any debugging is placed in the resume path, then it must have the
+ relevant clocks and peripherals setup before use (ie, bootloader).
+
+ For example, if you transmit a character from the UART, the baud
+ rate and uart controls must be setup beforehand.
+
+
+Configuration
+-------------
+
+ The S3C2410 specific configuration in `System Type` defines various
+ aspects of how the S3C2410 suspend and resume support is configured
+
+ `S3C2410 PM Suspend debug`
+
+ This option prints messages to the serial console before and after
+ the actual suspend, giving detailed information on what is
+ happening
+
+
+ `S3C2410 PM Suspend Memory CRC`
+
+ Allows the entire memory to be checksummed before and after the
+ suspend to see if there has been any corruption of the contents.
+
+ Note, the time to calculate the CRC is dependent on the CPU speed
+ and the size of memory. For an 64Mbyte RAM area on an 200MHz
+ S3C2410, this can take approximately 4 seconds to complete.
+
+ This support requires the CRC32 function to be enabled.
+
+
+ `S3C2410 PM Suspend CRC Chunksize (KiB)`
+
+ Defines the size of memory each CRC chunk covers. A smaller value
+ will mean that the CRC data block will take more memory, but will
+ identify any faults with better precision
+
+
+Document Author
+---------------
+
+Ben Dooks, Copyright 2004 Simtec Electronics
+
diff --git a/Documentation/arm/Samsung-S3C24XX/USB-Host.txt b/Documentation/arm/Samsung-S3C24XX/USB-Host.txt
new file mode 100644
index 00000000..f82b1fae
--- /dev/null
+++ b/Documentation/arm/Samsung-S3C24XX/USB-Host.txt
@@ -0,0 +1,93 @@
+ S3C24XX USB Host support
+ ========================
+
+
+
+Introduction
+------------
+
+ This document details the S3C2410/S3C2440 in-built OHCI USB host support.
+
+Configuration
+-------------
+
+ Enable at least the following kernel options:
+
+ menuconfig:
+
+ Device Drivers --->
+ USB support --->
+ <*> Support for Host-side USB
+ <*> OHCI HCD support
+
+
+ .config:
+ CONFIG_USB
+ CONFIG_USB_OHCI_HCD
+
+
+ Once these options are configured, the standard set of USB device
+ drivers can be configured and used.
+
+
+Board Support
+-------------
+
+ The driver attaches to a platform device, which will need to be
+ added by the board specific support file in linux/arch/arm/mach-s3c2410,
+ such as mach-bast.c or mach-smdk2410.c
+
+ The platform device's platform_data field is only needed if the
+ board implements extra power control or over-current monitoring.
+
+ The OHCI driver does not ensure the state of the S3C2410's MISCCTRL
+ register, so if both ports are to be used for the host, then it is
+ the board support file's responsibility to ensure that the second
+ port is configured to be connected to the OHCI core.
+
+
+Platform Data
+-------------
+
+ See arch/arm/mach-s3c2410/include/mach/usb-control.h for the
+ descriptions of the platform device data. An implementation
+ can be found in linux/arch/arm/mach-s3c2410/usb-simtec.c .
+
+ The `struct s3c2410_hcd_info` contains a pair of functions
+ that get called to enable over-current detection, and to
+ control the port power status.
+
+ The ports are numbered 0 and 1.
+
+ power_control:
+
+ Called to enable or disable the power on the port.
+
+ enable_oc:
+
+ Called to enable or disable the over-current monitoring.
+ This should claim or release the resources being used to
+ check the power condition on the port, such as an IRQ.
+
+ report_oc:
+
+ The OHCI driver fills this field in for the over-current code
+ to call when there is a change to the over-current state on
+ an port. The ports argument is a bitmask of 1 bit per port,
+ with bit X being 1 for an over-current on port X.
+
+ The function s3c2410_usb_report_oc() has been provided to
+ ensure this is called correctly.
+
+ port[x]:
+
+ This is struct describes each port, 0 or 1. The platform driver
+ should set the flags field of each port to S3C_HCDFLG_USED if
+ the port is enabled.
+
+
+
+Document Author
+---------------
+
+Ben Dooks, Copyright 2005 Simtec Electronics
diff --git a/Documentation/arm/Samsung/GPIO.txt b/Documentation/arm/Samsung/GPIO.txt
new file mode 100644
index 00000000..795adfd8
--- /dev/null
+++ b/Documentation/arm/Samsung/GPIO.txt
@@ -0,0 +1,40 @@
+ Samsung GPIO implementation
+ ===========================
+
+Introduction
+------------
+
+This outlines the Samsung GPIO implementation and the architecture
+specific calls provided alongside the drivers/gpio core.
+
+
+S3C24XX (Legacy)
+----------------
+
+See Documentation/arm/Samsung-S3C24XX/GPIO.txt for more information
+about these devices. Their implementation has been brought into line
+with the core samsung implementation described in this document.
+
+
+GPIOLIB integration
+-------------------
+
+The gpio implementation uses gpiolib as much as possible, only providing
+specific calls for the items that require Samsung specific handling, such
+as pin special-function or pull resistor control.
+
+GPIO numbering is synchronised between the Samsung and gpiolib system.
+
+
+PIN configuration
+-----------------
+
+Pin configuration is specific to the Samsung architecture, with each SoC
+registering the necessary information for the core gpio configuration
+implementation to configure pins as necessary.
+
+The s3c_gpio_cfgpin() and s3c_gpio_setpull() provide the means for a
+driver or machine to change gpio configuration.
+
+See arch/arm/plat-samsung/include/plat/gpio-cfg.h for more information
+on these functions.
diff --git a/Documentation/arm/Samsung/Overview.txt b/Documentation/arm/Samsung/Overview.txt
new file mode 100644
index 00000000..658abb25
--- /dev/null
+++ b/Documentation/arm/Samsung/Overview.txt
@@ -0,0 +1,97 @@
+ Samsung ARM Linux Overview
+ ==========================
+
+Introduction
+------------
+
+ The Samsung range of ARM SoCs spans many similar devices, from the initial
+ ARM9 through to the newest ARM cores. This document shows an overview of
+ the current kernel support, how to use it and where to find the code
+ that supports this.
+
+ The currently supported SoCs are:
+
+ - S3C24XX: See Documentation/arm/Samsung-S3C24XX/Overview.txt for full list
+ - S3C64XX: S3C6400 and S3C6410
+ - S5P6440
+ - S5PC100
+ - S5PC110 / S5PV210
+
+
+S3C24XX Systems
+---------------
+
+ There is still documentation in Documnetation/arm/Samsung-S3C24XX/ which
+ deals with the architecture and drivers specific to these devices.
+
+ See Documentation/arm/Samsung-S3C24XX/Overview.txt for more information
+ on the implementation details and specific support.
+
+
+Configuration
+-------------
+
+ A number of configurations are supplied, as there is no current way of
+ unifying all the SoCs into one kernel.
+
+ s5p6440_defconfig - S5P6440 specific default configuration
+ s5pc100_defconfig - S5PC100 specific default configuration
+ s5pc110_defconfig - S5PC110 specific default configuration
+ s5pv210_defconfig - S5PV210 specific default configuration
+
+
+Layout
+------
+
+ The directory layout is currently being restructured, and consists of
+ several platform directories and then the machine specific directories
+ of the CPUs being built for.
+
+ plat-samsung provides the base for all the implementations, and is the
+ last in the line of include directories that are processed for the build
+ specific information. It contains the base clock, GPIO and device definitions
+ to get the system running.
+
+ plat-s3c24xx is for s3c24xx specific builds, see the S3C24XX docs.
+
+ plat-s5p is for s5p specific builds, and contains common support for the
+ S5P specific systems. Not all S5Ps use all the features in this directory
+ due to differences in the hardware.
+
+
+Layout changes
+--------------
+
+ The old plat-s3c and plat-s5pc1xx directories have been removed, with
+ support moved to either plat-samsung or plat-s5p as necessary. These moves
+ where to simplify the include and dependency issues involved with having
+ so many different platform directories.
+
+ It was decided to remove plat-s5pc1xx as some of the support was already
+ in plat-s5p or plat-samsung, with the S5PC110 support added with S5PV210
+ the only user was the S5PC100. The S5PC100 specific items where moved to
+ arch/arm/mach-s5pc100.
+
+
+
+
+Port Contributors
+-----------------
+
+ Ben Dooks (BJD)
+ Vincent Sanders
+ Herbert Potzl
+ Arnaud Patard (RTP)
+ Roc Wu
+ Klaus Fetscher
+ Dimitry Andric
+ Shannon Holland
+ Guillaume Gourat (NexVision)
+ Christer Weinigel (wingel) (Acer N30)
+ Lucas Correia Villa Real (S3C2400 port)
+
+
+Document Author
+---------------
+
+Copyright 2009-2010 Ben Dooks <ben-linux@fluff.org>
diff --git a/Documentation/arm/Samsung/clksrc-change-registers.awk b/Documentation/arm/Samsung/clksrc-change-registers.awk
new file mode 100755
index 00000000..0c502208
--- /dev/null
+++ b/Documentation/arm/Samsung/clksrc-change-registers.awk
@@ -0,0 +1,167 @@
+#!/usr/bin/awk -f
+#
+# Copyright 2010 Ben Dooks <ben-linux@fluff.org>
+#
+# Released under GPLv2
+
+# example usage
+# ./clksrc-change-registers.awk arch/arm/plat-s5pc1xx/include/plat/regs-clock.h < src > dst
+
+function extract_value(s)
+{
+ eqat = index(s, "=")
+ comat = index(s, ",")
+ return substr(s, eqat+2, (comat-eqat)-2)
+}
+
+function remove_brackets(b)
+{
+ return substr(b, 2, length(b)-2)
+}
+
+function splitdefine(l, p)
+{
+ r = split(l, tp)
+
+ p[0] = tp[2]
+ p[1] = remove_brackets(tp[3])
+}
+
+function find_length(f)
+{
+ if (0)
+ printf "find_length " f "\n" > "/dev/stderr"
+
+ if (f ~ /0x1/)
+ return 1
+ else if (f ~ /0x3/)
+ return 2
+ else if (f ~ /0x7/)
+ return 3
+ else if (f ~ /0xf/)
+ return 4
+
+ printf "unknown legnth " f "\n" > "/dev/stderr"
+ exit
+}
+
+function find_shift(s)
+{
+ id = index(s, "<")
+ if (id <= 0) {
+ printf "cannot find shift " s "\n" > "/dev/stderr"
+ exit
+ }
+
+ return substr(s, id+2)
+}
+
+
+BEGIN {
+ if (ARGC < 2) {
+ print "too few arguments" > "/dev/stderr"
+ exit
+ }
+
+# read the header file and find the mask values that we will need
+# to replace and create an associative array of values
+
+ while (getline line < ARGV[1] > 0) {
+ if (line ~ /\#define.*_MASK/ &&
+ !(line ~ /S5PC100_EPLL_MASK/) &&
+ !(line ~ /USB_SIG_MASK/)) {
+ splitdefine(line, fields)
+ name = fields[0]
+ if (0)
+ printf "MASK " line "\n" > "/dev/stderr"
+ dmask[name,0] = find_length(fields[1])
+ dmask[name,1] = find_shift(fields[1])
+ if (0)
+ printf "=> '" name "' LENGTH=" dmask[name,0] " SHIFT=" dmask[name,1] "\n" > "/dev/stderr"
+ } else {
+ }
+ }
+
+ delete ARGV[1]
+}
+
+/clksrc_clk.*=.*{/ {
+ shift=""
+ mask=""
+ divshift=""
+ reg_div=""
+ reg_src=""
+ indent=1
+
+ print $0
+
+ for(; indent >= 1;) {
+ if ((getline line) <= 0) {
+ printf "unexpected end of file" > "/dev/stderr"
+ exit 1;
+ }
+
+ if (line ~ /\.shift/) {
+ shift = extract_value(line)
+ } else if (line ~ /\.mask/) {
+ mask = extract_value(line)
+ } else if (line ~ /\.reg_divider/) {
+ reg_div = extract_value(line)
+ } else if (line ~ /\.reg_source/) {
+ reg_src = extract_value(line)
+ } else if (line ~ /\.divider_shift/) {
+ divshift = extract_value(line)
+ } else if (line ~ /{/) {
+ indent++
+ print line
+ } else if (line ~ /}/) {
+ indent--
+
+ if (indent == 0) {
+ if (0) {
+ printf "shift '" shift "' ='" dmask[shift,0] "'\n" > "/dev/stderr"
+ printf "mask '" mask "'\n" > "/dev/stderr"
+ printf "dshft '" divshift "'\n" > "/dev/stderr"
+ printf "rdiv '" reg_div "'\n" > "/dev/stderr"
+ printf "rsrc '" reg_src "'\n" > "/dev/stderr"
+ }
+
+ generated = mask
+ sub(reg_src, reg_div, generated)
+
+ if (0) {
+ printf "/* rsrc " reg_src " */\n"
+ printf "/* rdiv " reg_div " */\n"
+ printf "/* shift " shift " */\n"
+ printf "/* mask " mask " */\n"
+ printf "/* generated " generated " */\n"
+ }
+
+ if (reg_div != "") {
+ printf "\t.reg_div = { "
+ printf ".reg = " reg_div ", "
+ printf ".shift = " dmask[generated,1] ", "
+ printf ".size = " dmask[generated,0] ", "
+ printf "},\n"
+ }
+
+ printf "\t.reg_src = { "
+ printf ".reg = " reg_src ", "
+ printf ".shift = " dmask[mask,1] ", "
+ printf ".size = " dmask[mask,0] ", "
+
+ printf "},\n"
+
+ }
+
+ print line
+ } else {
+ print line
+ }
+
+ if (0)
+ printf indent ":" line "\n" > "/dev/stderr"
+ }
+}
+
+// && ! /clksrc_clk.*=.*{/ { print $0 }
diff --git a/Documentation/arm/Setup b/Documentation/arm/Setup
new file mode 100644
index 00000000..0cb1e64b
--- /dev/null
+++ b/Documentation/arm/Setup
@@ -0,0 +1,129 @@
+Kernel initialisation parameters on ARM Linux
+---------------------------------------------
+
+The following document describes the kernel initialisation parameter
+structure, otherwise known as 'struct param_struct' which is used
+for most ARM Linux architectures.
+
+This structure is used to pass initialisation parameters from the
+kernel loader to the Linux kernel proper, and may be short lived
+through the kernel initialisation process. As a general rule, it
+should not be referenced outside of arch/arm/kernel/setup.c:setup_arch().
+
+There are a lot of parameters listed in there, and they are described
+below:
+
+ page_size
+
+ This parameter must be set to the page size of the machine, and
+ will be checked by the kernel.
+
+ nr_pages
+
+ This is the total number of pages of memory in the system. If
+ the memory is banked, then this should contain the total number
+ of pages in the system.
+
+ If the system contains separate VRAM, this value should not
+ include this information.
+
+ ramdisk_size
+
+ This is now obsolete, and should not be used.
+
+ flags
+
+ Various kernel flags, including:
+ bit 0 - 1 = mount root read only
+ bit 1 - unused
+ bit 2 - 0 = load ramdisk
+ bit 3 - 0 = prompt for ramdisk
+
+ rootdev
+
+ major/minor number pair of device to mount as the root filesystem.
+
+ video_num_cols
+ video_num_rows
+
+ These two together describe the character size of the dummy console,
+ or VGA console character size. They should not be used for any other
+ purpose.
+
+ It's generally a good idea to set these to be either standard VGA, or
+ the equivalent character size of your fbcon display. This then allows
+ all the bootup messages to be displayed correctly.
+
+ video_x
+ video_y
+
+ This describes the character position of cursor on VGA console, and
+ is otherwise unused. (should not be used for other console types, and
+ should not be used for other purposes).
+
+ memc_control_reg
+
+ MEMC chip control register for Acorn Archimedes and Acorn A5000
+ based machines. May be used differently by different architectures.
+
+ sounddefault
+
+ Default sound setting on Acorn machines. May be used differently by
+ different architectures.
+
+ adfsdrives
+
+ Number of ADFS/MFM disks. May be used differently by different
+ architectures.
+
+ bytes_per_char_h
+ bytes_per_char_v
+
+ These are now obsolete, and should not be used.
+
+ pages_in_bank[4]
+
+ Number of pages in each bank of the systems memory (used for RiscPC).
+ This is intended to be used on systems where the physical memory
+ is non-contiguous from the processors point of view.
+
+ pages_in_vram
+
+ Number of pages in VRAM (used on Acorn RiscPC). This value may also
+ be used by loaders if the size of the video RAM can't be obtained
+ from the hardware.
+
+ initrd_start
+ initrd_size
+
+ This describes the kernel virtual start address and size of the
+ initial ramdisk.
+
+ rd_start
+
+ Start address in sectors of the ramdisk image on a floppy disk.
+
+ system_rev
+
+ system revision number.
+
+ system_serial_low
+ system_serial_high
+
+ system 64-bit serial number
+
+ mem_fclk_21285
+
+ The speed of the external oscillator to the 21285 (footbridge),
+ which control's the speed of the memory bus, timer & serial port.
+ Depending upon the speed of the cpu its value can be between
+ 0-66 MHz. If no params are passed or a value of zero is passed,
+ then a value of 50 Mhz is the default on 21285 architectures.
+
+ paths[8][128]
+
+ These are now obsolete, and should not be used.
+
+ commandline
+
+ Kernel command line parameters. Details can be found elsewhere.
diff --git a/Documentation/arm/VFP/release-notes.txt b/Documentation/arm/VFP/release-notes.txt
new file mode 100644
index 00000000..28a27957
--- /dev/null
+++ b/Documentation/arm/VFP/release-notes.txt
@@ -0,0 +1,55 @@
+Release notes for Linux Kernel VFP support code
+-----------------------------------------------
+
+Date: 20 May 2004
+Author: Russell King
+
+This is the first release of the Linux Kernel VFP support code. It
+provides support for the exceptions bounced from VFP hardware found
+on ARM926EJ-S.
+
+This release has been validated against the SoftFloat-2b library by
+John R. Hauser using the TestFloat-2a test suite. Details of this
+library and test suite can be found at:
+
+ http://www.jhauser.us/arithmetic/SoftFloat.html
+
+The operations which have been tested with this package are:
+
+ - fdiv
+ - fsub
+ - fadd
+ - fmul
+ - fcmp
+ - fcmpe
+ - fcvtd
+ - fcvts
+ - fsito
+ - ftosi
+ - fsqrt
+
+All the above pass softfloat tests with the following exceptions:
+
+- fadd/fsub shows some differences in the handling of +0 / -0 results
+ when input operands differ in signs.
+- the handling of underflow exceptions is slightly different. If a
+ result underflows before rounding, but becomes a normalised number
+ after rounding, we do not signal an underflow exception.
+
+Other operations which have been tested by basic assembly-only tests
+are:
+
+ - fcpy
+ - fabs
+ - fneg
+ - ftoui
+ - ftosiz
+ - ftouiz
+
+The combination operations have not been tested:
+
+ - fmac
+ - fnmac
+ - fmsc
+ - fnmsc
+ - fnmul
diff --git a/Documentation/arm/cluster-pm-race-avoidance.txt b/Documentation/arm/cluster-pm-race-avoidance.txt
new file mode 100644
index 00000000..750b6fc2
--- /dev/null
+++ b/Documentation/arm/cluster-pm-race-avoidance.txt
@@ -0,0 +1,498 @@
+Cluster-wide Power-up/power-down race avoidance algorithm
+=========================================================
+
+This file documents the algorithm which is used to coordinate CPU and
+cluster setup and teardown operations and to manage hardware coherency
+controls safely.
+
+The section "Rationale" explains what the algorithm is for and why it is
+needed. "Basic model" explains general concepts using a simplified view
+of the system. The other sections explain the actual details of the
+algorithm in use.
+
+
+Rationale
+---------
+
+In a system containing multiple CPUs, it is desirable to have the
+ability to turn off individual CPUs when the system is idle, reducing
+power consumption and thermal dissipation.
+
+In a system containing multiple clusters of CPUs, it is also desirable
+to have the ability to turn off entire clusters.
+
+Turning entire clusters off and on is a risky business, because it
+involves performing potentially destructive operations affecting a group
+of independently running CPUs, while the OS continues to run. This
+means that we need some coordination in order to ensure that critical
+cluster-level operations are only performed when it is truly safe to do
+so.
+
+Simple locking may not be sufficient to solve this problem, because
+mechanisms like Linux spinlocks may rely on coherency mechanisms which
+are not immediately enabled when a cluster powers up. Since enabling or
+disabling those mechanisms may itself be a non-atomic operation (such as
+writing some hardware registers and invalidating large caches), other
+methods of coordination are required in order to guarantee safe
+power-down and power-up at the cluster level.
+
+The mechanism presented in this document describes a coherent memory
+based protocol for performing the needed coordination. It aims to be as
+lightweight as possible, while providing the required safety properties.
+
+
+Basic model
+-----------
+
+Each cluster and CPU is assigned a state, as follows:
+
+ DOWN
+ COMING_UP
+ UP
+ GOING_DOWN
+
+ +---------> UP ----------+
+ | v
+
+ COMING_UP GOING_DOWN
+
+ ^ |
+ +--------- DOWN <--------+
+
+
+DOWN: The CPU or cluster is not coherent, and is either powered off or
+ suspended, or is ready to be powered off or suspended.
+
+COMING_UP: The CPU or cluster has committed to moving to the UP state.
+ It may be part way through the process of initialisation and
+ enabling coherency.
+
+UP: The CPU or cluster is active and coherent at the hardware
+ level. A CPU in this state is not necessarily being used
+ actively by the kernel.
+
+GOING_DOWN: The CPU or cluster has committed to moving to the DOWN
+ state. It may be part way through the process of teardown and
+ coherency exit.
+
+
+Each CPU has one of these states assigned to it at any point in time.
+The CPU states are described in the "CPU state" section, below.
+
+Each cluster is also assigned a state, but it is necessary to split the
+state value into two parts (the "cluster" state and "inbound" state) and
+to introduce additional states in order to avoid races between different
+CPUs in the cluster simultaneously modifying the state. The cluster-
+level states are described in the "Cluster state" section.
+
+To help distinguish the CPU states from cluster states in this
+discussion, the state names are given a CPU_ prefix for the CPU states,
+and a CLUSTER_ or INBOUND_ prefix for the cluster states.
+
+
+CPU state
+---------
+
+In this algorithm, each individual core in a multi-core processor is
+referred to as a "CPU". CPUs are assumed to be single-threaded:
+therefore, a CPU can only be doing one thing at a single point in time.
+
+This means that CPUs fit the basic model closely.
+
+The algorithm defines the following states for each CPU in the system:
+
+ CPU_DOWN
+ CPU_COMING_UP
+ CPU_UP
+ CPU_GOING_DOWN
+
+ cluster setup and
+ CPU setup complete policy decision
+ +-----------> CPU_UP ------------+
+ | v
+
+ CPU_COMING_UP CPU_GOING_DOWN
+
+ ^ |
+ +----------- CPU_DOWN <----------+
+ policy decision CPU teardown complete
+ or hardware event
+
+
+The definitions of the four states correspond closely to the states of
+the basic model.
+
+Transitions between states occur as follows.
+
+A trigger event (spontaneous) means that the CPU can transition to the
+next state as a result of making local progress only, with no
+requirement for any external event to happen.
+
+
+CPU_DOWN:
+
+ A CPU reaches the CPU_DOWN state when it is ready for
+ power-down. On reaching this state, the CPU will typically
+ power itself down or suspend itself, via a WFI instruction or a
+ firmware call.
+
+ Next state: CPU_COMING_UP
+ Conditions: none
+
+ Trigger events:
+
+ a) an explicit hardware power-up operation, resulting
+ from a policy decision on another CPU;
+
+ b) a hardware event, such as an interrupt.
+
+
+CPU_COMING_UP:
+
+ A CPU cannot start participating in hardware coherency until the
+ cluster is set up and coherent. If the cluster is not ready,
+ then the CPU will wait in the CPU_COMING_UP state until the
+ cluster has been set up.
+
+ Next state: CPU_UP
+ Conditions: The CPU's parent cluster must be in CLUSTER_UP.
+ Trigger events: Transition of the parent cluster to CLUSTER_UP.
+
+ Refer to the "Cluster state" section for a description of the
+ CLUSTER_UP state.
+
+
+CPU_UP:
+ When a CPU reaches the CPU_UP state, it is safe for the CPU to
+ start participating in local coherency.
+
+ This is done by jumping to the kernel's CPU resume code.
+
+ Note that the definition of this state is slightly different
+ from the basic model definition: CPU_UP does not mean that the
+ CPU is coherent yet, but it does mean that it is safe to resume
+ the kernel. The kernel handles the rest of the resume
+ procedure, so the remaining steps are not visible as part of the
+ race avoidance algorithm.
+
+ The CPU remains in this state until an explicit policy decision
+ is made to shut down or suspend the CPU.
+
+ Next state: CPU_GOING_DOWN
+ Conditions: none
+ Trigger events: explicit policy decision
+
+
+CPU_GOING_DOWN:
+
+ While in this state, the CPU exits coherency, including any
+ operations required to achieve this (such as cleaning data
+ caches).
+
+ Next state: CPU_DOWN
+ Conditions: local CPU teardown complete
+ Trigger events: (spontaneous)
+
+
+Cluster state
+-------------
+
+A cluster is a group of connected CPUs with some common resources.
+Because a cluster contains multiple CPUs, it can be doing multiple
+things at the same time. This has some implications. In particular, a
+CPU can start up while another CPU is tearing the cluster down.
+
+In this discussion, the "outbound side" is the view of the cluster state
+as seen by a CPU tearing the cluster down. The "inbound side" is the
+view of the cluster state as seen by a CPU setting the CPU up.
+
+In order to enable safe coordination in such situations, it is important
+that a CPU which is setting up the cluster can advertise its state
+independently of the CPU which is tearing down the cluster. For this
+reason, the cluster state is split into two parts:
+
+ "cluster" state: The global state of the cluster; or the state
+ on the outbound side:
+
+ CLUSTER_DOWN
+ CLUSTER_UP
+ CLUSTER_GOING_DOWN
+
+ "inbound" state: The state of the cluster on the inbound side.
+
+ INBOUND_NOT_COMING_UP
+ INBOUND_COMING_UP
+
+
+ The different pairings of these states results in six possible
+ states for the cluster as a whole:
+
+ CLUSTER_UP
+ +==========> INBOUND_NOT_COMING_UP -------------+
+ # |
+ |
+ CLUSTER_UP <----+ |
+ INBOUND_COMING_UP | v
+
+ ^ CLUSTER_GOING_DOWN CLUSTER_GOING_DOWN
+ # INBOUND_COMING_UP <=== INBOUND_NOT_COMING_UP
+
+ CLUSTER_DOWN | |
+ INBOUND_COMING_UP <----+ |
+ |
+ ^ |
+ +=========== CLUSTER_DOWN <------------+
+ INBOUND_NOT_COMING_UP
+
+ Transitions -----> can only be made by the outbound CPU, and
+ only involve changes to the "cluster" state.
+
+ Transitions ===##> can only be made by the inbound CPU, and only
+ involve changes to the "inbound" state, except where there is no
+ further transition possible on the outbound side (i.e., the
+ outbound CPU has put the cluster into the CLUSTER_DOWN state).
+
+ The race avoidance algorithm does not provide a way to determine
+ which exact CPUs within the cluster play these roles. This must
+ be decided in advance by some other means. Refer to the section
+ "Last man and first man selection" for more explanation.
+
+
+ CLUSTER_DOWN/INBOUND_NOT_COMING_UP is the only state where the
+ cluster can actually be powered down.
+
+ The parallelism of the inbound and outbound CPUs is observed by
+ the existence of two different paths from CLUSTER_GOING_DOWN/
+ INBOUND_NOT_COMING_UP (corresponding to GOING_DOWN in the basic
+ model) to CLUSTER_DOWN/INBOUND_COMING_UP (corresponding to
+ COMING_UP in the basic model). The second path avoids cluster
+ teardown completely.
+
+ CLUSTER_UP/INBOUND_COMING_UP is equivalent to UP in the basic
+ model. The final transition to CLUSTER_UP/INBOUND_NOT_COMING_UP
+ is trivial and merely resets the state machine ready for the
+ next cycle.
+
+ Details of the allowable transitions follow.
+
+ The next state in each case is notated
+
+ <cluster state>/<inbound state> (<transitioner>)
+
+ where the <transitioner> is the side on which the transition
+ can occur; either the inbound or the outbound side.
+
+
+CLUSTER_DOWN/INBOUND_NOT_COMING_UP:
+
+ Next state: CLUSTER_DOWN/INBOUND_COMING_UP (inbound)
+ Conditions: none
+ Trigger events:
+
+ a) an explicit hardware power-up operation, resulting
+ from a policy decision on another CPU;
+
+ b) a hardware event, such as an interrupt.
+
+
+CLUSTER_DOWN/INBOUND_COMING_UP:
+
+ In this state, an inbound CPU sets up the cluster, including
+ enabling of hardware coherency at the cluster level and any
+ other operations (such as cache invalidation) which are required
+ in order to achieve this.
+
+ The purpose of this state is to do sufficient cluster-level
+ setup to enable other CPUs in the cluster to enter coherency
+ safely.
+
+ Next state: CLUSTER_UP/INBOUND_COMING_UP (inbound)
+ Conditions: cluster-level setup and hardware coherency complete
+ Trigger events: (spontaneous)
+
+
+CLUSTER_UP/INBOUND_COMING_UP:
+
+ Cluster-level setup is complete and hardware coherency is
+ enabled for the cluster. Other CPUs in the cluster can safely
+ enter coherency.
+
+ This is a transient state, leading immediately to
+ CLUSTER_UP/INBOUND_NOT_COMING_UP. All other CPUs on the cluster
+ should consider treat these two states as equivalent.
+
+ Next state: CLUSTER_UP/INBOUND_NOT_COMING_UP (inbound)
+ Conditions: none
+ Trigger events: (spontaneous)
+
+
+CLUSTER_UP/INBOUND_NOT_COMING_UP:
+
+ Cluster-level setup is complete and hardware coherency is
+ enabled for the cluster. Other CPUs in the cluster can safely
+ enter coherency.
+
+ The cluster will remain in this state until a policy decision is
+ made to power the cluster down.
+
+ Next state: CLUSTER_GOING_DOWN/INBOUND_NOT_COMING_UP (outbound)
+ Conditions: none
+ Trigger events: policy decision to power down the cluster
+
+
+CLUSTER_GOING_DOWN/INBOUND_NOT_COMING_UP:
+
+ An outbound CPU is tearing the cluster down. The selected CPU
+ must wait in this state until all CPUs in the cluster are in the
+ CPU_DOWN state.
+
+ When all CPUs are in the CPU_DOWN state, the cluster can be torn
+ down, for example by cleaning data caches and exiting
+ cluster-level coherency.
+
+ To avoid wasteful unnecessary teardown operations, the outbound
+ should check the inbound cluster state for asynchronous
+ transitions to INBOUND_COMING_UP. Alternatively, individual
+ CPUs can be checked for entry into CPU_COMING_UP or CPU_UP.
+
+
+ Next states:
+
+ CLUSTER_DOWN/INBOUND_NOT_COMING_UP (outbound)
+ Conditions: cluster torn down and ready to power off
+ Trigger events: (spontaneous)
+
+ CLUSTER_GOING_DOWN/INBOUND_COMING_UP (inbound)
+ Conditions: none
+ Trigger events:
+
+ a) an explicit hardware power-up operation,
+ resulting from a policy decision on another
+ CPU;
+
+ b) a hardware event, such as an interrupt.
+
+
+CLUSTER_GOING_DOWN/INBOUND_COMING_UP:
+
+ The cluster is (or was) being torn down, but another CPU has
+ come online in the meantime and is trying to set up the cluster
+ again.
+
+ If the outbound CPU observes this state, it has two choices:
+
+ a) back out of teardown, restoring the cluster to the
+ CLUSTER_UP state;
+
+ b) finish tearing the cluster down and put the cluster
+ in the CLUSTER_DOWN state; the inbound CPU will
+ set up the cluster again from there.
+
+ Choice (a) permits the removal of some latency by avoiding
+ unnecessary teardown and setup operations in situations where
+ the cluster is not really going to be powered down.
+
+
+ Next states:
+
+ CLUSTER_UP/INBOUND_COMING_UP (outbound)
+ Conditions: cluster-level setup and hardware
+ coherency complete
+ Trigger events: (spontaneous)
+
+ CLUSTER_DOWN/INBOUND_COMING_UP (outbound)
+ Conditions: cluster torn down and ready to power off
+ Trigger events: (spontaneous)
+
+
+Last man and First man selection
+--------------------------------
+
+The CPU which performs cluster tear-down operations on the outbound side
+is commonly referred to as the "last man".
+
+The CPU which performs cluster setup on the inbound side is commonly
+referred to as the "first man".
+
+The race avoidance algorithm documented above does not provide a
+mechanism to choose which CPUs should play these roles.
+
+
+Last man:
+
+When shutting down the cluster, all the CPUs involved are initially
+executing Linux and hence coherent. Therefore, ordinary spinlocks can
+be used to select a last man safely, before the CPUs become
+non-coherent.
+
+
+First man:
+
+Because CPUs may power up asynchronously in response to external wake-up
+events, a dynamic mechanism is needed to make sure that only one CPU
+attempts to play the first man role and do the cluster-level
+initialisation: any other CPUs must wait for this to complete before
+proceeding.
+
+Cluster-level initialisation may involve actions such as configuring
+coherency controls in the bus fabric.
+
+The current implementation in mcpm_head.S uses a separate mutual exclusion
+mechanism to do this arbitration. This mechanism is documented in
+detail in vlocks.txt.
+
+
+Features and Limitations
+------------------------
+
+Implementation:
+
+ The current ARM-based implementation is split between
+ arch/arm/common/mcpm_head.S (low-level inbound CPU operations) and
+ arch/arm/common/mcpm_entry.c (everything else):
+
+ __mcpm_cpu_going_down() signals the transition of a CPU to the
+ CPU_GOING_DOWN state.
+
+ __mcpm_cpu_down() signals the transition of a CPU to the CPU_DOWN
+ state.
+
+ A CPU transitions to CPU_COMING_UP and then to CPU_UP via the
+ low-level power-up code in mcpm_head.S. This could
+ involve CPU-specific setup code, but in the current
+ implementation it does not.
+
+ __mcpm_outbound_enter_critical() and __mcpm_outbound_leave_critical()
+ handle transitions from CLUSTER_UP to CLUSTER_GOING_DOWN
+ and from there to CLUSTER_DOWN or back to CLUSTER_UP (in
+ the case of an aborted cluster power-down).
+
+ These functions are more complex than the __mcpm_cpu_*()
+ functions due to the extra inter-CPU coordination which
+ is needed for safe transitions at the cluster level.
+
+ A cluster transitions from CLUSTER_DOWN back to CLUSTER_UP via
+ the low-level power-up code in mcpm_head.S. This
+ typically involves platform-specific setup code,
+ provided by the platform-specific power_up_setup
+ function registered via mcpm_sync_init.
+
+Deep topologies:
+
+ As currently described and implemented, the algorithm does not
+ support CPU topologies involving more than two levels (i.e.,
+ clusters of clusters are not supported). The algorithm could be
+ extended by replicating the cluster-level states for the
+ additional topological levels, and modifying the transition
+ rules for the intermediate (non-outermost) cluster levels.
+
+
+Colophon
+--------
+
+Originally created and documented by Dave Martin for Linaro Limited, in
+collaboration with Nicolas Pitre and Achin Gupta.
+
+Copyright (C) 2012-2013 Linaro Limited
+Distributed under the terms of Version 2 of the GNU General Public
+License, as defined in linux/COPYING.
diff --git a/Documentation/arm/kernel_user_helpers.txt b/Documentation/arm/kernel_user_helpers.txt
new file mode 100644
index 00000000..56735947
--- /dev/null
+++ b/Documentation/arm/kernel_user_helpers.txt
@@ -0,0 +1,267 @@
+Kernel-provided User Helpers
+============================
+
+These are segment of kernel provided user code reachable from user space
+at a fixed address in kernel memory. This is used to provide user space
+with some operations which require kernel help because of unimplemented
+native feature and/or instructions in many ARM CPUs. The idea is for this
+code to be executed directly in user mode for best efficiency but which is
+too intimate with the kernel counter part to be left to user libraries.
+In fact this code might even differ from one CPU to another depending on
+the available instruction set, or whether it is a SMP systems. In other
+words, the kernel reserves the right to change this code as needed without
+warning. Only the entry points and their results as documented here are
+guaranteed to be stable.
+
+This is different from (but doesn't preclude) a full blown VDSO
+implementation, however a VDSO would prevent some assembly tricks with
+constants that allows for efficient branching to those code segments. And
+since those code segments only use a few cycles before returning to user
+code, the overhead of a VDSO indirect far call would add a measurable
+overhead to such minimalistic operations.
+
+User space is expected to bypass those helpers and implement those things
+inline (either in the code emitted directly by the compiler, or part of
+the implementation of a library call) when optimizing for a recent enough
+processor that has the necessary native support, but only if resulting
+binaries are already to be incompatible with earlier ARM processors due to
+usage of similar native instructions for other things. In other words
+don't make binaries unable to run on earlier processors just for the sake
+of not using these kernel helpers if your compiled code is not going to
+use new instructions for other purpose.
+
+New helpers may be added over time, so an older kernel may be missing some
+helpers present in a newer kernel. For this reason, programs must check
+the value of __kuser_helper_version (see below) before assuming that it is
+safe to call any particular helper. This check should ideally be
+performed only once at process startup time, and execution aborted early
+if the required helpers are not provided by the kernel version that
+process is running on.
+
+kuser_helper_version
+--------------------
+
+Location: 0xffff0ffc
+
+Reference declaration:
+
+ extern int32_t __kuser_helper_version;
+
+Definition:
+
+ This field contains the number of helpers being implemented by the
+ running kernel. User space may read this to determine the availability
+ of a particular helper.
+
+Usage example:
+
+#define __kuser_helper_version (*(int32_t *)0xffff0ffc)
+
+void check_kuser_version(void)
+{
+ if (__kuser_helper_version < 2) {
+ fprintf(stderr, "can't do atomic operations, kernel too old\n");
+ abort();
+ }
+}
+
+Notes:
+
+ User space may assume that the value of this field never changes
+ during the lifetime of any single process. This means that this
+ field can be read once during the initialisation of a library or
+ startup phase of a program.
+
+kuser_get_tls
+-------------
+
+Location: 0xffff0fe0
+
+Reference prototype:
+
+ void * __kuser_get_tls(void);
+
+Input:
+
+ lr = return address
+
+Output:
+
+ r0 = TLS value
+
+Clobbered registers:
+
+ none
+
+Definition:
+
+ Get the TLS value as previously set via the __ARM_NR_set_tls syscall.
+
+Usage example:
+
+typedef void * (__kuser_get_tls_t)(void);
+#define __kuser_get_tls (*(__kuser_get_tls_t *)0xffff0fe0)
+
+void foo()
+{
+ void *tls = __kuser_get_tls();
+ printf("TLS = %p\n", tls);
+}
+
+Notes:
+
+ - Valid only if __kuser_helper_version >= 1 (from kernel version 2.6.12).
+
+kuser_cmpxchg
+-------------
+
+Location: 0xffff0fc0
+
+Reference prototype:
+
+ int __kuser_cmpxchg(int32_t oldval, int32_t newval, volatile int32_t *ptr);
+
+Input:
+
+ r0 = oldval
+ r1 = newval
+ r2 = ptr
+ lr = return address
+
+Output:
+
+ r0 = success code (zero or non-zero)
+ C flag = set if r0 == 0, clear if r0 != 0
+
+Clobbered registers:
+
+ r3, ip, flags
+
+Definition:
+
+ Atomically store newval in *ptr only if *ptr is equal to oldval.
+ Return zero if *ptr was changed or non-zero if no exchange happened.
+ The C flag is also set if *ptr was changed to allow for assembly
+ optimization in the calling code.
+
+Usage example:
+
+typedef int (__kuser_cmpxchg_t)(int oldval, int newval, volatile int *ptr);
+#define __kuser_cmpxchg (*(__kuser_cmpxchg_t *)0xffff0fc0)
+
+int atomic_add(volatile int *ptr, int val)
+{
+ int old, new;
+
+ do {
+ old = *ptr;
+ new = old + val;
+ } while(__kuser_cmpxchg(old, new, ptr));
+
+ return new;
+}
+
+Notes:
+
+ - This routine already includes memory barriers as needed.
+
+ - Valid only if __kuser_helper_version >= 2 (from kernel version 2.6.12).
+
+kuser_memory_barrier
+--------------------
+
+Location: 0xffff0fa0
+
+Reference prototype:
+
+ void __kuser_memory_barrier(void);
+
+Input:
+
+ lr = return address
+
+Output:
+
+ none
+
+Clobbered registers:
+
+ none
+
+Definition:
+
+ Apply any needed memory barrier to preserve consistency with data modified
+ manually and __kuser_cmpxchg usage.
+
+Usage example:
+
+typedef void (__kuser_dmb_t)(void);
+#define __kuser_dmb (*(__kuser_dmb_t *)0xffff0fa0)
+
+Notes:
+
+ - Valid only if __kuser_helper_version >= 3 (from kernel version 2.6.15).
+
+kuser_cmpxchg64
+---------------
+
+Location: 0xffff0f60
+
+Reference prototype:
+
+ int __kuser_cmpxchg64(const int64_t *oldval,
+ const int64_t *newval,
+ volatile int64_t *ptr);
+
+Input:
+
+ r0 = pointer to oldval
+ r1 = pointer to newval
+ r2 = pointer to target value
+ lr = return address
+
+Output:
+
+ r0 = success code (zero or non-zero)
+ C flag = set if r0 == 0, clear if r0 != 0
+
+Clobbered registers:
+
+ r3, lr, flags
+
+Definition:
+
+ Atomically store the 64-bit value pointed by *newval in *ptr only if *ptr
+ is equal to the 64-bit value pointed by *oldval. Return zero if *ptr was
+ changed or non-zero if no exchange happened.
+
+ The C flag is also set if *ptr was changed to allow for assembly
+ optimization in the calling code.
+
+Usage example:
+
+typedef int (__kuser_cmpxchg64_t)(const int64_t *oldval,
+ const int64_t *newval,
+ volatile int64_t *ptr);
+#define __kuser_cmpxchg64 (*(__kuser_cmpxchg64_t *)0xffff0f60)
+
+int64_t atomic_add64(volatile int64_t *ptr, int64_t val)
+{
+ int64_t old, new;
+
+ do {
+ old = *ptr;
+ new = old + val;
+ } while(__kuser_cmpxchg64(&old, &new, ptr));
+
+ return new;
+}
+
+Notes:
+
+ - This routine already includes memory barriers as needed.
+
+ - Due to the length of this sequence, this spans 2 conventional kuser
+ "slots", therefore 0xffff0f80 is not used as a valid entry point.
+
+ - Valid only if __kuser_helper_version >= 5 (from kernel version 3.1).
diff --git a/Documentation/arm/mem_alignment b/Documentation/arm/mem_alignment
new file mode 100644
index 00000000..c7c7a114
--- /dev/null
+++ b/Documentation/arm/mem_alignment
@@ -0,0 +1,58 @@
+Too many problems poped up because of unnoticed misaligned memory access in
+kernel code lately. Therefore the alignment fixup is now unconditionally
+configured in for SA11x0 based targets. According to Alan Cox, this is a
+bad idea to configure it out, but Russell King has some good reasons for
+doing so on some f***ed up ARM architectures like the EBSA110. However
+this is not the case on many design I'm aware of, like all SA11x0 based
+ones.
+
+Of course this is a bad idea to rely on the alignment trap to perform
+unaligned memory access in general. If those access are predictable, you
+are better to use the macros provided by include/asm/unaligned.h. The
+alignment trap can fixup misaligned access for the exception cases, but at
+a high performance cost. It better be rare.
+
+Now for user space applications, it is possible to configure the alignment
+trap to SIGBUS any code performing unaligned access (good for debugging bad
+code), or even fixup the access by software like for kernel code. The later
+mode isn't recommended for performance reasons (just think about the
+floating point emulation that works about the same way). Fix your code
+instead!
+
+Please note that randomly changing the behaviour without good thought is
+real bad - it changes the behaviour of all unaligned instructions in user
+space, and might cause programs to fail unexpectedly.
+
+To change the alignment trap behavior, simply echo a number into
+/proc/cpu/alignment. The number is made up from various bits:
+
+bit behavior when set
+--- -----------------
+
+0 A user process performing an unaligned memory access
+ will cause the kernel to print a message indicating
+ process name, pid, pc, instruction, address, and the
+ fault code.
+
+1 The kernel will attempt to fix up the user process
+ performing the unaligned access. This is of course
+ slow (think about the floating point emulator) and
+ not recommended for production use.
+
+2 The kernel will send a SIGBUS signal to the user process
+ performing the unaligned access.
+
+Note that not all combinations are supported - only values 0 through 5.
+(6 and 7 don't make sense).
+
+For example, the following will turn on the warnings, but without
+fixing up or sending SIGBUS signals:
+
+ echo 1 > /proc/sys/debug/alignment
+
+You can also read the content of the same file to get statistical
+information on unaligned access occurrences plus the current mode of
+operation for user space code.
+
+
+Nicolas Pitre, Mar 13, 2001. Modified Russell King, Nov 30, 2001.
diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt
new file mode 100644
index 00000000..4bfb9ffb
--- /dev/null
+++ b/Documentation/arm/memory.txt
@@ -0,0 +1,95 @@
+ Kernel Memory Layout on ARM Linux
+
+ Russell King <rmk@arm.linux.org.uk>
+ November 17, 2005 (2.6.15)
+
+This document describes the virtual memory layout which the Linux
+kernel uses for ARM processors. It indicates which regions are
+free for platforms to use, and which are used by generic code.
+
+The ARM CPU is capable of addressing a maximum of 4GB virtual memory
+space, and this must be shared between user space processes, the
+kernel, and hardware devices.
+
+As the ARM architecture matures, it becomes necessary to reserve
+certain regions of VM space for use for new facilities; therefore
+this document may reserve more VM space over time.
+
+Start End Use
+--------------------------------------------------------------------------
+ffff8000 ffffffff copy_user_page / clear_user_page use.
+ For SA11xx and Xscale, this is used to
+ setup a minicache mapping.
+
+ffff4000 ffffffff cache aliasing on ARMv6 and later CPUs.
+
+ffff1000 ffff7fff Reserved.
+ Platforms must not use this address range.
+
+ffff0000 ffff0fff CPU vector page.
+ The CPU vectors are mapped here if the
+ CPU supports vector relocation (control
+ register V bit.)
+
+fffe0000 fffeffff XScale cache flush area. This is used
+ in proc-xscale.S to flush the whole data
+ cache. (XScale does not have TCM.)
+
+fffe8000 fffeffff DTCM mapping area for platforms with
+ DTCM mounted inside the CPU.
+
+fffe0000 fffe7fff ITCM mapping area for platforms with
+ ITCM mounted inside the CPU.
+
+fff00000 fffdffff Fixmap mapping region. Addresses provided
+ by fix_to_virt() will be located here.
+
+ffc00000 ffefffff DMA memory mapping region. Memory returned
+ by the dma_alloc_xxx functions will be
+ dynamically mapped here.
+
+ff000000 ffbfffff Reserved for future expansion of DMA
+ mapping region.
+
+fee00000 feffffff Mapping of PCI I/O space. This is a static
+ mapping within the vmalloc space.
+
+VMALLOC_START VMALLOC_END-1 vmalloc() / ioremap() space.
+ Memory returned by vmalloc/ioremap will
+ be dynamically placed in this region.
+ Machine specific static mappings are also
+ located here through iotable_init().
+ VMALLOC_START is based upon the value
+ of the high_memory variable, and VMALLOC_END
+ is equal to 0xff000000.
+
+PAGE_OFFSET high_memory-1 Kernel direct-mapped RAM region.
+ This maps the platforms RAM, and typically
+ maps all platform RAM in a 1:1 relationship.
+
+PKMAP_BASE PAGE_OFFSET-1 Permanent kernel mappings
+ One way of mapping HIGHMEM pages into kernel
+ space.
+
+MODULES_VADDR MODULES_END-1 Kernel module space
+ Kernel modules inserted via insmod are
+ placed here using dynamic mappings.
+
+00001000 TASK_SIZE-1 User space mappings
+ Per-thread mappings are placed here via
+ the mmap() system call.
+
+00000000 00000fff CPU vector page / null pointer trap
+ CPUs which do not support vector remapping
+ place their vector page here. NULL pointer
+ dereferences by both the kernel and user
+ space are also caught via this mapping.
+
+Please note that mappings which collide with the above areas may result
+in a non-bootable kernel, or may cause the kernel to (eventually) panic
+at run time.
+
+Since future CPUs may impact the kernel mapping layout, user programs
+must not access any memory which is not mapped inside their 0x0001000
+to TASK_SIZE address range. If they wish to access these areas, they
+must set up their own mappings using open() and mmap().
diff --git a/Documentation/arm/msm/gpiomux.txt b/Documentation/arm/msm/gpiomux.txt
new file mode 100644
index 00000000..67a81620
--- /dev/null
+++ b/Documentation/arm/msm/gpiomux.txt
@@ -0,0 +1,176 @@
+This document provides an overview of the msm_gpiomux interface, which
+is used to provide gpio pin multiplexing and configuration on mach-msm
+targets.
+
+History
+=======
+
+The first-generation API for gpio configuration & multiplexing on msm
+is the function gpio_tlmm_config(). This function has a few notable
+shortcomings, which led to its deprecation and replacement by gpiomux:
+
+The 'disable' parameter: Setting the second parameter to
+gpio_tlmm_config to GPIO_CFG_DISABLE tells the peripheral
+processor in charge of the subsystem to perform a look-up into a
+low-power table and apply the low-power/sleep setting for the pin.
+As the msm family evolved this became problematic. Not all pins
+have sleep settings, not all peripheral processors will accept requests
+to apply said sleep settings, and not all msm targets have their gpio
+subsystems managed by a peripheral processor. In order to get consistent
+behavior on all targets, drivers are forced to ignore this parameter,
+rendering it useless.
+
+The 'direction' flag: for all mux-settings other than raw-gpio (0),
+the output-enable bit of a gpio is hard-wired to a known
+input (usually VDD or ground). For those settings, the direction flag
+is meaningless at best, and deceptive at worst. In addition, using the
+direction flag to change output-enable (OE) directly can cause trouble in
+gpiolib, which has no visibility into gpio direction changes made
+in this way. Direction control in gpio mode should be made through gpiolib.
+
+Key Features of gpiomux
+=======================
+
+- A consistent interface across all generations of msm. Drivers can expect
+the same results on every target.
+- gpiomux plays nicely with gpiolib. Functions that should belong to gpiolib
+are left to gpiolib and not duplicated here. gpiomux is written with the
+intent that gpio_chips will call gpiomux reference-counting methods
+from their request() and free() hooks, providing full integration.
+- Tabular configuration. Instead of having to call gpio_tlmm_config
+hundreds of times, gpio configuration is placed in a single table.
+- Per-gpio sleep. Each gpio is individually reference counted, allowing only
+those lines which are in use to be put in high-power states.
+- 0 means 'do nothing': all flags are designed so that the default memset-zero
+equates to a sensible default of 'no configuration', preventing users
+from having to provide hundreds of 'no-op' configs for unused or
+unwanted lines.
+
+Usage
+=====
+
+To use gpiomux, provide configuration information for relevant gpio lines
+in the msm_gpiomux_configs table. Since a 0 equates to "unconfigured",
+only those lines to be managed by gpiomux need to be specified. Here
+is a completely fictional example:
+
+struct msm_gpiomux_config msm_gpiomux_configs[GPIOMUX_NGPIOS] = {
+ [12] = {
+ .active = GPIOMUX_VALID | GPIOMUX_DRV_8MA | GPIOMUX_FUNC_1,
+ .suspended = GPIOMUX_VALID | GPIOMUX_PULL_DOWN,
+ },
+ [34] = {
+ .suspended = GPIOMUX_VALID | GPIOMUX_PULL_DOWN,
+ },
+};
+
+To indicate that a gpio is in use, call msm_gpiomux_get() to increase
+its reference count. To decrease the reference count, call msm_gpiomux_put().
+
+The effect of this configuration is as follows:
+
+When the system boots, gpios 12 and 34 will be initialized with their
+'suspended' configurations. All other gpios, which were left unconfigured,
+will not be touched.
+
+When msm_gpiomux_get() is called on gpio 12 to raise its reference count
+above 0, its active configuration will be applied. Since no other gpio
+line has a valid active configuration, msm_gpiomux_get() will have no
+effect on any other line.
+
+When msm_gpiomux_put() is called on gpio 12 or 34 to drop their reference
+count to 0, their suspended configurations will be applied.
+Since no other gpio line has a valid suspended configuration, no other
+gpio line will be effected by msm_gpiomux_put(). Since gpio 34 has no valid
+active configuration, this is effectively a no-op for gpio 34 as well,
+with one small caveat, see the section "About Output-Enable Settings".
+
+All of the GPIOMUX_VALID flags may seem like unnecessary overhead, but
+they address some important issues. As unused entries (all those
+except 12 and 34) are zero-filled, gpiomux needs a way to distinguish
+the used fields from the unused. In addition, the all-zero pattern
+is a valid configuration! Therefore, gpiomux defines an additional bit
+which is used to indicate when a field is used. This has the pleasant
+side-effect of allowing calls to msm_gpiomux_write to use '0' to indicate
+that a value should not be changed:
+
+ msm_gpiomux_write(0, GPIOMUX_VALID, 0);
+
+replaces the active configuration of gpio 0 with an all-zero configuration,
+but leaves the suspended configuration as it was.
+
+Static Configurations
+=====================
+
+To install a static configuration, which is applied at boot and does
+not change after that, install a configuration with a suspended component
+but no active component, as in the previous example:
+
+ [34] = {
+ .suspended = GPIOMUX_VALID | GPIOMUX_PULL_DOWN,
+ },
+
+The suspended setting is applied during boot, and the lack of any valid
+active setting prevents any other setting from being applied at runtime.
+If other subsystems attempting to access the line is a concern, one could
+*really* anchor the configuration down by calling msm_gpiomux_get on the
+line at initialization to move the line into active mode. With the line
+held, it will never be re-suspended, and with no valid active configuration,
+no new configurations will be applied.
+
+But then, if having other subsystems grabbing for the line is truly a concern,
+it should be reserved with gpio_request instead, which carries an implicit
+msm_gpiomux_get.
+
+gpiomux and gpiolib
+===================
+
+It is expected that msm gpio_chips will call msm_gpiomux_get() and
+msm_gpiomux_put() from their request and free hooks, like this fictional
+example:
+
+static int request(struct gpio_chip *chip, unsigned offset)
+{
+ return msm_gpiomux_get(chip->base + offset);
+}
+
+static void free(struct gpio_chip *chip, unsigned offset)
+{
+ msm_gpiomux_put(chip->base + offset);
+}
+
+ ...somewhere in a gpio_chip declaration...
+ .request = request,
+ .free = free,
+
+This provides important functionality:
+- It guarantees that a gpio line will have its 'active' config applied
+ when the line is requested, and will not be suspended while the line
+ remains requested; and
+- It guarantees that gpio-direction settings from gpiolib behave sensibly.
+ See "About Output-Enable Settings."
+
+This mechanism allows for "auto-request" of gpiomux lines via gpiolib
+when it is suitable. Drivers wishing more exact control are, of course,
+free to also use msm_gpiomux_set and msm_gpiomux_get.
+
+About Output-Enable Settings
+============================
+
+Some msm targets do not have the ability to query the current gpio
+configuration setting. This means that changes made to the output-enable
+(OE) bit by gpiolib cannot be consistently detected and preserved by gpiomux.
+Therefore, when gpiomux applies a configuration setting, any direction
+settings which may have been applied by gpiolib are lost and the default
+input settings are re-applied.
+
+For this reason, drivers should not assume that gpio direction settings
+continue to hold if they free and then re-request a gpio. This seems like
+common sense - after all, anybody could have obtained the line in the
+meantime - but it needs saying.
+
+This also means that calls to msm_gpiomux_write will reset the OE bit,
+which means that if the gpio line is held by a client of gpiolib and
+msm_gpiomux_write is called, the direction setting has been lost and
+gpiolib's internal state has been broken.
+Release gpio lines before reconfiguring them.
diff --git a/Documentation/arm/nwfpe/NOTES b/Documentation/arm/nwfpe/NOTES
new file mode 100644
index 00000000..40577b5a
--- /dev/null
+++ b/Documentation/arm/nwfpe/NOTES
@@ -0,0 +1,29 @@
+There seems to be a problem with exp(double) and our emulator. I haven't
+been able to track it down yet. This does not occur with the emulator
+supplied by Russell King.
+
+I also found one oddity in the emulator. I don't think it is serious but
+will point it out. The ARM calling conventions require floating point
+registers f4-f7 to be preserved over a function call. The compiler quite
+often uses an stfe instruction to save f4 on the stack upon entry to a
+function, and an ldfe instruction to restore it before returning.
+
+I was looking at some code, that calculated a double result, stored it in f4
+then made a function call. Upon return from the function call the number in
+f4 had been converted to an extended value in the emulator.
+
+This is a side effect of the stfe instruction. The double in f4 had to be
+converted to extended, then stored. If an lfm/sfm combination had been used,
+then no conversion would occur. This has performance considerations. The
+result from the function call and f4 were used in a multiplication. If the
+emulator sees a multiply of a double and extended, it promotes the double to
+extended, then does the multiply in extended precision.
+
+This code will cause this problem:
+
+double x, y, z;
+z = log(x)/log(y);
+
+The result of log(x) (a double) will be calculated, returned in f0, then
+moved to f4 to preserve it over the log(y) call. The division will be done
+in extended precision, due to the stfe instruction used to save f4 in log(y).
diff --git a/Documentation/arm/nwfpe/README b/Documentation/arm/nwfpe/README
new file mode 100644
index 00000000..771871de
--- /dev/null
+++ b/Documentation/arm/nwfpe/README
@@ -0,0 +1,70 @@
+This directory contains the version 0.92 test release of the NetWinder
+Floating Point Emulator.
+
+The majority of the code was written by me, Scott Bambrough It is
+written in C, with a small number of routines in inline assembler
+where required. It was written quickly, with a goal of implementing a
+working version of all the floating point instructions the compiler
+emits as the first target. I have attempted to be as optimal as
+possible, but there remains much room for improvement.
+
+I have attempted to make the emulator as portable as possible. One of
+the problems is with leading underscores on kernel symbols. Elf
+kernels have no leading underscores, a.out compiled kernels do. I
+have attempted to use the C_SYMBOL_NAME macro wherever this may be
+important.
+
+Another choice I made was in the file structure. I have attempted to
+contain all operating system specific code in one module (fpmodule.*).
+All the other files contain emulator specific code. This should allow
+others to port the emulator to NetBSD for instance relatively easily.
+
+The floating point operations are based on SoftFloat Release 2, by
+John Hauser. SoftFloat is a software implementation of floating-point
+that conforms to the IEC/IEEE Standard for Binary Floating-point
+Arithmetic. As many as four formats are supported: single precision,
+double precision, extended double precision, and quadruple precision.
+All operations required by the standard are implemented, except for
+conversions to and from decimal. We use only the single precision,
+double precision and extended double precision formats. The port of
+SoftFloat to the ARM was done by Phil Blundell, based on an earlier
+port of SoftFloat version 1 by Neil Carson for NetBSD/arm32.
+
+The file README.FPE contains a description of what has been implemented
+so far in the emulator. The file TODO contains a information on what
+remains to be done, and other ideas for the emulator.
+
+Bug reports, comments, suggestions should be directed to me at
+<scottb@netwinder.org>. General reports of "this program doesn't
+work correctly when your emulator is installed" are useful for
+determining that bugs still exist; but are virtually useless when
+attempting to isolate the problem. Please report them, but don't
+expect quick action. Bugs still exist. The problem remains in isolating
+which instruction contains the bug. Small programs illustrating a specific
+problem are a godsend.
+
+Legal Notices
+-------------
+
+The NetWinder Floating Point Emulator is free software. Everything Rebel.com
+has written is provided under the GNU GPL. See the file COPYING for copying
+conditions. Excluded from the above is the SoftFloat code. John Hauser's
+legal notice for SoftFloat is included below.
+
+-------------------------------------------------------------------------------
+SoftFloat Legal Notice
+
+SoftFloat was written by John R. Hauser. This work was made possible in
+part by the International Computer Science Institute, located at Suite 600,
+1947 Center Street, Berkeley, California 94704. Funding was partially
+provided by the National Science Foundation under grant MIP-9311980. The
+original version of this code was written as part of a project to build
+a fixed-point vector processor in collaboration with the University of
+California at Berkeley, overseen by Profs. Nelson Morgan and John Wawrzynek.
+
+THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort
+has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
+TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO
+PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
+AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
+-------------------------------------------------------------------------------
diff --git a/Documentation/arm/nwfpe/README.FPE b/Documentation/arm/nwfpe/README.FPE
new file mode 100644
index 00000000..26f5d7bb
--- /dev/null
+++ b/Documentation/arm/nwfpe/README.FPE
@@ -0,0 +1,156 @@
+The following describes the current state of the NetWinder's floating point
+emulator.
+
+In the following nomenclature is used to describe the floating point
+instructions. It follows the conventions in the ARM manual.
+
+<S|D|E> = <single|double|extended>, no default
+{P|M|Z} = {round to +infinity,round to -infinity,round to zero},
+ default = round to nearest
+
+Note: items enclosed in {} are optional.
+
+Floating Point Coprocessor Data Transfer Instructions (CPDT)
+------------------------------------------------------------
+
+LDF/STF - load and store floating
+
+<LDF|STF>{cond}<S|D|E> Fd, Rn
+<LDF|STF>{cond}<S|D|E> Fd, [Rn, #<expression>]{!}
+<LDF|STF>{cond}<S|D|E> Fd, [Rn], #<expression>
+
+These instructions are fully implemented.
+
+LFM/SFM - load and store multiple floating
+
+Form 1 syntax:
+<LFM|SFM>{cond}<S|D|E> Fd, <count>, [Rn]
+<LFM|SFM>{cond}<S|D|E> Fd, <count>, [Rn, #<expression>]{!}
+<LFM|SFM>{cond}<S|D|E> Fd, <count>, [Rn], #<expression>
+
+Form 2 syntax:
+<LFM|SFM>{cond}<FD,EA> Fd, <count>, [Rn]{!}
+
+These instructions are fully implemented. They store/load three words
+for each floating point register into the memory location given in the
+instruction. The format in memory is unlikely to be compatible with
+other implementations, in particular the actual hardware. Specific
+mention of this is made in the ARM manuals.
+
+Floating Point Coprocessor Register Transfer Instructions (CPRT)
+----------------------------------------------------------------
+
+Conversions, read/write status/control register instructions
+
+FLT{cond}<S,D,E>{P,M,Z} Fn, Rd Convert integer to floating point
+FIX{cond}{P,M,Z} Rd, Fn Convert floating point to integer
+WFS{cond} Rd Write floating point status register
+RFS{cond} Rd Read floating point status register
+WFC{cond} Rd Write floating point control register
+RFC{cond} Rd Read floating point control register
+
+FLT/FIX are fully implemented.
+
+RFS/WFS are fully implemented.
+
+RFC/WFC are fully implemented. RFC/WFC are supervisor only instructions, and
+presently check the CPU mode, and do an invalid instruction trap if not called
+from supervisor mode.
+
+Compare instructions
+
+CMF{cond} Fn, Fm Compare floating
+CMFE{cond} Fn, Fm Compare floating with exception
+CNF{cond} Fn, Fm Compare negated floating
+CNFE{cond} Fn, Fm Compare negated floating with exception
+
+These are fully implemented.
+
+Floating Point Coprocessor Data Instructions (CPDT)
+---------------------------------------------------
+
+Dyadic operations:
+
+ADF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - add
+SUF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - subtract
+RSF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - reverse subtract
+MUF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - multiply
+DVF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - divide
+RDV{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - reverse divide
+
+These are fully implemented.
+
+FML{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - fast multiply
+FDV{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - fast divide
+FRD{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - fast reverse divide
+
+These are fully implemented as well. They use the same algorithm as the
+non-fast versions. Hence, in this implementation their performance is
+equivalent to the MUF/DVF/RDV instructions. This is acceptable according
+to the ARM manual. The manual notes these are defined only for single
+operands, on the actual FPA11 hardware they do not work for double or
+extended precision operands. The emulator currently does not check
+the requested permissions conditions, and performs the requested operation.
+
+RMF{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - IEEE remainder
+
+This is fully implemented.
+
+Monadic operations:
+
+MVF{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - move
+MNF{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - move negated
+
+These are fully implemented.
+
+ABS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - absolute value
+SQT{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - square root
+RND{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - round
+
+These are fully implemented.
+
+URD{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - unnormalized round
+NRM{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - normalize
+
+These are implemented. URD is implemented using the same code as the RND
+instruction. Since URD cannot return a unnormalized number, NRM becomes
+a NOP.
+
+Library calls:
+
+POW{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - power
+RPW{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - reverse power
+POL{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - polar angle (arctan2)
+
+LOG{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - logarithm to base 10
+LGN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - logarithm to base e
+EXP{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - exponent
+SIN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - sine
+COS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - cosine
+TAN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - tangent
+ASN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arcsine
+ACS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arccosine
+ATN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arctangent
+
+These are not implemented. They are not currently issued by the compiler,
+and are handled by routines in libc. These are not implemented by the FPA11
+hardware, but are handled by the floating point support code. They should
+be implemented in future versions.
+
+Signalling:
+
+Signals are implemented. However current ELF kernels produced by Rebel.com
+have a bug in them that prevents the module from generating a SIGFPE. This
+is caused by a failure to alias fp_current to the kernel variable
+current_set[0] correctly.
+
+The kernel provided with this distribution (vmlinux-nwfpe-0.93) contains
+a fix for this problem and also incorporates the current version of the
+emulator directly. It is possible to run with no floating point module
+loaded with this kernel. It is provided as a demonstration of the
+technology and for those who want to do floating point work that depends
+on signals. It is not strictly necessary to use the module.
+
+A module (either the one provided by Russell King, or the one in this
+distribution) can be loaded to replace the functionality of the emulator
+built into the kernel.
diff --git a/Documentation/arm/nwfpe/TODO b/Documentation/arm/nwfpe/TODO
new file mode 100644
index 00000000..8027061b
--- /dev/null
+++ b/Documentation/arm/nwfpe/TODO
@@ -0,0 +1,67 @@
+TODO LIST
+---------
+
+POW{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - power
+RPW{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - reverse power
+POL{cond}<S|D|E>{P,M,Z} Fd, Fn, <Fm,#value> - polar angle (arctan2)
+
+LOG{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - logarithm to base 10
+LGN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - logarithm to base e
+EXP{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - exponent
+SIN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - sine
+COS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - cosine
+TAN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - tangent
+ASN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arcsine
+ACS{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arccosine
+ATN{cond}<S|D|E>{P,M,Z} Fd, <Fm,#value> - arctangent
+
+These are not implemented. They are not currently issued by the compiler,
+and are handled by routines in libc. These are not implemented by the FPA11
+hardware, but are handled by the floating point support code. They should
+be implemented in future versions.
+
+There are a couple of ways to approach the implementation of these. One
+method would be to use accurate table methods for these routines. I have
+a couple of papers by S. Gal from IBM's research labs in Haifa, Israel that
+seem to promise extreme accuracy (in the order of 99.8%) and reasonable speed.
+These methods are used in GLIBC for some of the transcendental functions.
+
+Another approach, which I know little about is CORDIC. This stands for
+Coordinate Rotation Digital Computer, and is a method of computing
+transcendental functions using mostly shifts and adds and a few
+multiplications and divisions. The ARM excels at shifts and adds,
+so such a method could be promising, but requires more research to
+determine if it is feasible.
+
+Rounding Methods
+
+The IEEE standard defines 4 rounding modes. Round to nearest is the
+default, but rounding to + or - infinity or round to zero are also allowed.
+Many architectures allow the rounding mode to be specified by modifying bits
+in a control register. Not so with the ARM FPA11 architecture. To change
+the rounding mode one must specify it with each instruction.
+
+This has made porting some benchmarks difficult. It is possible to
+introduce such a capability into the emulator. The FPCR contains
+bits describing the rounding mode. The emulator could be altered to
+examine a flag, which if set forced it to ignore the rounding mode in
+the instruction, and use the mode specified in the bits in the FPCR.
+
+This would require a method of getting/setting the flag, and the bits
+in the FPCR. This requires a kernel call in ArmLinux, as WFC/RFC are
+supervisor only instructions. If anyone has any ideas or comments I
+would like to hear them.
+
+[NOTE: pulled out from some docs on ARM floating point, specifically
+ for the Acorn FPE, but not limited to it:
+
+ The floating point control register (FPCR) may only be present in some
+ implementations: it is there to control the hardware in an implementation-
+ specific manner, for example to disable the floating point system. The user
+ mode of the ARM is not permitted to use this register (since the right is
+ reserved to alter it between implementations) and the WFC and RFC
+ instructions will trap if tried in user mode.
+
+ Hence, the answer is yes, you could do this, but then you will run a high
+ risk of becoming isolated if and when hardware FP emulation comes out
+ -- Russell].
diff --git a/Documentation/arm/pxa/mfp.txt b/Documentation/arm/pxa/mfp.txt
new file mode 100644
index 00000000..a179e5bc
--- /dev/null
+++ b/Documentation/arm/pxa/mfp.txt
@@ -0,0 +1,286 @@
+ MFP Configuration for PXA2xx/PXA3xx Processors
+
+ Eric Miao <eric.miao@marvell.com>
+
+MFP stands for Multi-Function Pin, which is the pin-mux logic on PXA3xx and
+later PXA series processors. This document describes the existing MFP API,
+and how board/platform driver authors could make use of it.
+
+ Basic Concept
+===============
+
+Unlike the GPIO alternate function settings on PXA25x and PXA27x, a new MFP
+mechanism is introduced from PXA3xx to completely move the pin-mux functions
+out of the GPIO controller. In addition to pin-mux configurations, the MFP
+also controls the low power state, driving strength, pull-up/down and event
+detection of each pin. Below is a diagram of internal connections between
+the MFP logic and the remaining SoC peripherals:
+
+ +--------+
+ | |--(GPIO19)--+
+ | GPIO | |
+ | |--(GPIO...) |
+ +--------+ |
+ | +---------+
+ +--------+ +------>| |
+ | PWM2 |--(PWM_OUT)-------->| MFP |
+ +--------+ +------>| |-------> to external PAD
+ | +---->| |
+ +--------+ | | +-->| |
+ | SSP2 |---(TXD)----+ | | +---------+
+ +--------+ | |
+ | |
+ +--------+ | |
+ | Keypad |--(MKOUT4)----+ |
+ +--------+ |
+ |
+ +--------+ |
+ | UART2 |---(TXD)--------+
+ +--------+
+
+NOTE: the external pad is named as MFP_PIN_GPIO19, it doesn't necessarily
+mean it's dedicated for GPIO19, only as a hint that internally this pin
+can be routed from GPIO19 of the GPIO controller.
+
+To better understand the change from PXA25x/PXA27x GPIO alternate function
+to this new MFP mechanism, here are several key points:
+
+ 1. GPIO controller on PXA3xx is now a dedicated controller, same as other
+ internal controllers like PWM, SSP and UART, with 128 internal signals
+ which can be routed to external through one or more MFPs (e.g. GPIO<0>
+ can be routed through either MFP_PIN_GPIO0 as well as MFP_PIN_GPIO0_2,
+ see arch/arm/mach-pxa/mach/include/mfp-pxa300.h)
+
+ 2. Alternate function configuration is removed from this GPIO controller,
+ the remaining functions are pure GPIO-specific, i.e.
+
+ - GPIO signal level control
+ - GPIO direction control
+ - GPIO level change detection
+
+ 3. Low power state for each pin is now controlled by MFP, this means the
+ PGSRx registers on PXA2xx are now useless on PXA3xx
+
+ 4. Wakeup detection is now controlled by MFP, PWER does not control the
+ wakeup from GPIO(s) any more, depending on the sleeping state, ADxER
+ (as defined in pxa3xx-regs.h) controls the wakeup from MFP
+
+NOTE: with such a clear separation of MFP and GPIO, by GPIO<xx> we normally
+mean it is a GPIO signal, and by MFP<xxx> or pin xxx, we mean a physical
+pad (or ball).
+
+ MFP API Usage
+===============
+
+For board code writers, here are some guidelines:
+
+1. include ONE of the following header files in your <board>.c:
+
+ - #include <mach/mfp-pxa25x.h>
+ - #include <mach/mfp-pxa27x.h>
+ - #include <mach/mfp-pxa300.h>
+ - #include <mach/mfp-pxa320.h>
+ - #include <mach/mfp-pxa930.h>
+
+ NOTE: only one file in your <board>.c, depending on the processors used,
+ because pin configuration definitions may conflict in these file (i.e.
+ same name, different meaning and settings on different processors). E.g.
+ for zylonite platform, which support both PXA300/PXA310 and PXA320, two
+ separate files are introduced: zylonite_pxa300.c and zylonite_pxa320.c
+ (in addition to handle MFP configuration differences, they also handle
+ the other differences between the two combinations).
+
+ NOTE: PXA300 and PXA310 are almost identical in pin configurations (with
+ PXA310 supporting some additional ones), thus the difference is actually
+ covered in a single mfp-pxa300.h.
+
+2. prepare an array for the initial pin configurations, e.g.:
+
+ static unsigned long mainstone_pin_config[] __initdata = {
+ /* Chip Select */
+ GPIO15_nCS_1,
+
+ /* LCD - 16bpp Active TFT */
+ GPIOxx_TFT_LCD_16BPP,
+ GPIO16_PWM0_OUT, /* Backlight */
+
+ /* MMC */
+ GPIO32_MMC_CLK,
+ GPIO112_MMC_CMD,
+ GPIO92_MMC_DAT_0,
+ GPIO109_MMC_DAT_1,
+ GPIO110_MMC_DAT_2,
+ GPIO111_MMC_DAT_3,
+
+ ...
+
+ /* GPIO */
+ GPIO1_GPIO | WAKEUP_ON_EDGE_BOTH,
+ };
+
+ a) once the pin configurations are passed to pxa{2xx,3xx}_mfp_config(),
+ and written to the actual registers, they are useless and may discard,
+ adding '__initdata' will help save some additional bytes here.
+
+ b) when there is only one possible pin configurations for a component,
+ some simplified definitions can be used, e.g. GPIOxx_TFT_LCD_16BPP on
+ PXA25x and PXA27x processors
+
+ c) if by board design, a pin can be configured to wake up the system
+ from low power state, it can be 'OR'ed with any of:
+
+ WAKEUP_ON_EDGE_BOTH
+ WAKEUP_ON_EDGE_RISE
+ WAKEUP_ON_EDGE_FALL
+ WAKEUP_ON_LEVEL_HIGH - specifically for enabling of keypad GPIOs,
+
+ to indicate that this pin has the capability of wake-up the system,
+ and on which edge(s). This, however, doesn't necessarily mean the
+ pin _will_ wakeup the system, it will only when set_irq_wake() is
+ invoked with the corresponding GPIO IRQ (GPIO_IRQ(xx) or gpio_to_irq())
+ and eventually calls gpio_set_wake() for the actual register setting.
+
+ d) although PXA3xx MFP supports edge detection on each pin, the
+ internal logic will only wakeup the system when those specific bits
+ in ADxER registers are set, which can be well mapped to the
+ corresponding peripheral, thus set_irq_wake() can be called with
+ the peripheral IRQ to enable the wakeup.
+
+
+ MFP on PXA3xx
+===============
+
+Every external I/O pad on PXA3xx (excluding those for special purpose) has
+one MFP logic associated, and is controlled by one MFP register (MFPR).
+
+The MFPR has the following bit definitions (for PXA300/PXA310/PXA320):
+
+ 31 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+ +-------------------------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ | RESERVED |PS|PU|PD| DRIVE |SS|SD|SO|EC|EF|ER|--| AF_SEL |
+ +-------------------------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+
+ Bit 3: RESERVED
+ Bit 4: EDGE_RISE_EN - enable detection of rising edge on this pin
+ Bit 5: EDGE_FALL_EN - enable detection of falling edge on this pin
+ Bit 6: EDGE_CLEAR - disable edge detection on this pin
+ Bit 7: SLEEP_OE_N - enable outputs during low power modes
+ Bit 8: SLEEP_DATA - output data on the pin during low power modes
+ Bit 9: SLEEP_SEL - selection control for low power modes signals
+ Bit 13: PULLDOWN_EN - enable the internal pull-down resistor on this pin
+ Bit 14: PULLUP_EN - enable the internal pull-up resistor on this pin
+ Bit 15: PULL_SEL - pull state controlled by selected alternate function
+ (0) or by PULL{UP,DOWN}_EN bits (1)
+
+ Bit 0 - 2: AF_SEL - alternate function selection, 8 possibilities, from 0-7
+ Bit 10-12: DRIVE - drive strength and slew rate
+ 0b000 - fast 1mA
+ 0b001 - fast 2mA
+ 0b002 - fast 3mA
+ 0b003 - fast 4mA
+ 0b004 - slow 6mA
+ 0b005 - fast 6mA
+ 0b006 - slow 10mA
+ 0b007 - fast 10mA
+
+ MFP Design for PXA2xx/PXA3xx
+==============================
+
+Due to the difference of pin-mux handling between PXA2xx and PXA3xx, a unified
+MFP API is introduced to cover both series of processors.
+
+The basic idea of this design is to introduce definitions for all possible pin
+configurations, these definitions are processor and platform independent, and
+the actual API invoked to convert these definitions into register settings and
+make them effective there-after.
+
+ Files Involved
+ --------------
+
+ - arch/arm/mach-pxa/include/mach/mfp.h
+
+ for
+ 1. Unified pin definitions - enum constants for all configurable pins
+ 2. processor-neutral bit definitions for a possible MFP configuration
+
+ - arch/arm/mach-pxa/include/mach/mfp-pxa3xx.h
+
+ for PXA3xx specific MFPR register bit definitions and PXA3xx common pin
+ configurations
+
+ - arch/arm/mach-pxa/include/mach/mfp-pxa2xx.h
+
+ for PXA2xx specific definitions and PXA25x/PXA27x common pin configurations
+
+ - arch/arm/mach-pxa/include/mach/mfp-pxa25x.h
+ arch/arm/mach-pxa/include/mach/mfp-pxa27x.h
+ arch/arm/mach-pxa/include/mach/mfp-pxa300.h
+ arch/arm/mach-pxa/include/mach/mfp-pxa320.h
+ arch/arm/mach-pxa/include/mach/mfp-pxa930.h
+
+ for processor specific definitions
+
+ - arch/arm/mach-pxa/mfp-pxa3xx.c
+ - arch/arm/mach-pxa/mfp-pxa2xx.c
+
+ for implementation of the pin configuration to take effect for the actual
+ processor.
+
+ Pin Configuration
+ -----------------
+
+ The following comments are copied from mfp.h (see the actual source code
+ for most updated info)
+
+ /*
+ * a possible MFP configuration is represented by a 32-bit integer
+ *
+ * bit 0.. 9 - MFP Pin Number (1024 Pins Maximum)
+ * bit 10..12 - Alternate Function Selection
+ * bit 13..15 - Drive Strength
+ * bit 16..18 - Low Power Mode State
+ * bit 19..20 - Low Power Mode Edge Detection
+ * bit 21..22 - Run Mode Pull State
+ *
+ * to facilitate the definition, the following macros are provided
+ *
+ * MFP_CFG_DEFAULT - default MFP configuration value, with
+ * alternate function = 0,
+ * drive strength = fast 3mA (MFP_DS03X)
+ * low power mode = default
+ * edge detection = none
+ *
+ * MFP_CFG - default MFPR value with alternate function
+ * MFP_CFG_DRV - default MFPR value with alternate function and
+ * pin drive strength
+ * MFP_CFG_LPM - default MFPR value with alternate function and
+ * low power mode
+ * MFP_CFG_X - default MFPR value with alternate function,
+ * pin drive strength and low power mode
+ */
+
+ Examples of pin configurations are:
+
+ #define GPIO94_SSP3_RXD MFP_CFG_X(GPIO94, AF1, DS08X, FLOAT)
+
+ which reads GPIO94 can be configured as SSP3_RXD, with alternate function
+ selection of 1, driving strength of 0b101, and a float state in low power
+ modes.
+
+ NOTE: this is the default setting of this pin being configured as SSP3_RXD
+ which can be modified a bit in board code, though it is not recommended to
+ do so, simply because this default setting is usually carefully encoded,
+ and is supposed to work in most cases.
+
+ Register Settings
+ -----------------
+
+ Register settings on PXA3xx for a pin configuration is actually very
+ straight-forward, most bits can be converted directly into MFPR value
+ in a easier way. Two sets of MFPR values are calculated: the run-time
+ ones and the low power mode ones, to allow different settings.
+
+ The conversion from a generic pin configuration to the actual register
+ settings on PXA2xx is a bit complicated: many registers are involved,
+ including GAFRx, GPDRx, PGSRx, PWER, PKWR, PFER and PRER. Please see
+ mfp-pxa2xx.c for how the conversion is made.
diff --git a/Documentation/arm/sunxi/README b/Documentation/arm/sunxi/README
new file mode 100644
index 00000000..87a1e8fb
--- /dev/null
+++ b/Documentation/arm/sunxi/README
@@ -0,0 +1,19 @@
+ARM Allwinner SoCs
+==================
+
+This document lists all the ARM Allwinner SoCs that are currently
+supported in mainline by the Linux kernel. This document will also
+provide links to documentation and or datasheet for these SoCs.
+
+SunXi family
+------------
+
+ Flavors:
+ Allwinner A10 (sun4i)
+ Datasheet : http://dl.linux-sunxi.org/A10/A10%20Datasheet%20-%20v1.21%20%282012-04-06%29.pdf
+
+ Allwinner A13 (sun5i)
+ Datasheet : http://dl.linux-sunxi.org/A13/A13%20Datasheet%20-%20v1.12%20%282012-03-29%29.pdf
+
+ Core: Cortex A8
+ Linux kernel mach directory: arch/arm/mach-sunxi \ No newline at end of file
diff --git a/Documentation/arm/swp_emulation b/Documentation/arm/swp_emulation
new file mode 100644
index 00000000..af903d22
--- /dev/null
+++ b/Documentation/arm/swp_emulation
@@ -0,0 +1,27 @@
+Software emulation of deprecated SWP instruction (CONFIG_SWP_EMULATE)
+---------------------------------------------------------------------
+
+ARMv6 architecture deprecates use of the SWP/SWPB instructions, and recommeds
+moving to the load-locked/store-conditional instructions LDREX and STREX.
+
+ARMv7 multiprocessing extensions introduce the ability to disable these
+instructions, triggering an undefined instruction exception when executed.
+Trapped instructions are emulated using an LDREX/STREX or LDREXB/STREXB
+sequence. If a memory access fault (an abort) occurs, a segmentation fault is
+signalled to the triggering process.
+
+/proc/cpu/swp_emulation holds some statistics/information, including the PID of
+the last process to trigger the emulation to be invocated. For example:
+---
+Emulated SWP: 12
+Emulated SWPB: 0
+Aborted SWP{B}: 1
+Last process: 314
+---
+
+NOTE: when accessing uncached shared regions, LDREX/STREX rely on an external
+transaction monitoring block called a global monitor to maintain update
+atomicity. If your system does not implement a global monitor, this option can
+cause programs that perform SWP operations to uncached memory to deadlock, as
+the STREX operation will always fail.
+
diff --git a/Documentation/arm/tcm.txt b/Documentation/arm/tcm.txt
new file mode 100644
index 00000000..7c15871c
--- /dev/null
+++ b/Documentation/arm/tcm.txt
@@ -0,0 +1,155 @@
+ARM TCM (Tightly-Coupled Memory) handling in Linux
+----
+Written by Linus Walleij <linus.walleij@stericsson.com>
+
+Some ARM SoC:s have a so-called TCM (Tightly-Coupled Memory).
+This is usually just a few (4-64) KiB of RAM inside the ARM
+processor.
+
+Due to being embedded inside the CPU The TCM has a
+Harvard-architecture, so there is an ITCM (instruction TCM)
+and a DTCM (data TCM). The DTCM can not contain any
+instructions, but the ITCM can actually contain data.
+The size of DTCM or ITCM is minimum 4KiB so the typical
+minimum configuration is 4KiB ITCM and 4KiB DTCM.
+
+ARM CPU:s have special registers to read out status, physical
+location and size of TCM memories. arch/arm/include/asm/cputype.h
+defines a CPUID_TCM register that you can read out from the
+system control coprocessor. Documentation from ARM can be found
+at http://infocenter.arm.com, search for "TCM Status Register"
+to see documents for all CPUs. Reading this register you can
+determine if ITCM (bits 1-0) and/or DTCM (bit 17-16) is present
+in the machine.
+
+There is further a TCM region register (search for "TCM Region
+Registers" at the ARM site) that can report and modify the location
+size of TCM memories at runtime. This is used to read out and modify
+TCM location and size. Notice that this is not a MMU table: you
+actually move the physical location of the TCM around. At the
+place you put it, it will mask any underlying RAM from the
+CPU so it is usually wise not to overlap any physical RAM with
+the TCM.
+
+The TCM memory can then be remapped to another address again using
+the MMU, but notice that the TCM if often used in situations where
+the MMU is turned off. To avoid confusion the current Linux
+implementation will map the TCM 1 to 1 from physical to virtual
+memory in the location specified by the kernel. Currently Linux
+will map ITCM to 0xfffe0000 and on, and DTCM to 0xfffe8000 and
+on, supporting a maximum of 32KiB of ITCM and 32KiB of DTCM.
+
+Newer versions of the region registers also support dividing these
+TCMs in two separate banks, so for example an 8KiB ITCM is divided
+into two 4KiB banks with its own control registers. The idea is to
+be able to lock and hide one of the banks for use by the secure
+world (TrustZone).
+
+TCM is used for a few things:
+
+- FIQ and other interrupt handlers that need deterministic
+ timing and cannot wait for cache misses.
+
+- Idle loops where all external RAM is set to self-refresh
+ retention mode, so only on-chip RAM is accessible by
+ the CPU and then we hang inside ITCM waiting for an
+ interrupt.
+
+- Other operations which implies shutting off or reconfiguring
+ the external RAM controller.
+
+There is an interface for using TCM on the ARM architecture
+in <asm/tcm.h>. Using this interface it is possible to:
+
+- Define the physical address and size of ITCM and DTCM.
+
+- Tag functions to be compiled into ITCM.
+
+- Tag data and constants to be allocated to DTCM and ITCM.
+
+- Have the remaining TCM RAM added to a special
+ allocation pool with gen_pool_create() and gen_pool_add()
+ and provice tcm_alloc() and tcm_free() for this
+ memory. Such a heap is great for things like saving
+ device state when shutting off device power domains.
+
+A machine that has TCM memory shall select HAVE_TCM from
+arch/arm/Kconfig for itself. Code that needs to use TCM shall
+#include <asm/tcm.h>
+
+Functions to go into itcm can be tagged like this:
+int __tcmfunc foo(int bar);
+
+Since these are marked to become long_calls and you may want
+to have functions called locally inside the TCM without
+wasting space, there is also the __tcmlocalfunc prefix that
+will make the call relative.
+
+Variables to go into dtcm can be tagged like this:
+int __tcmdata foo;
+
+Constants can be tagged like this:
+int __tcmconst foo;
+
+To put assembler into TCM just use
+.section ".tcm.text" or .section ".tcm.data"
+respectively.
+
+Example code:
+
+#include <asm/tcm.h>
+
+/* Uninitialized data */
+static u32 __tcmdata tcmvar;
+/* Initialized data */
+static u32 __tcmdata tcmassigned = 0x2BADBABEU;
+/* Constant */
+static const u32 __tcmconst tcmconst = 0xCAFEBABEU;
+
+static void __tcmlocalfunc tcm_to_tcm(void)
+{
+ int i;
+ for (i = 0; i < 100; i++)
+ tcmvar ++;
+}
+
+static void __tcmfunc hello_tcm(void)
+{
+ /* Some abstract code that runs in ITCM */
+ int i;
+ for (i = 0; i < 100; i++) {
+ tcmvar ++;
+ }
+ tcm_to_tcm();
+}
+
+static void __init test_tcm(void)
+{
+ u32 *tcmem;
+ int i;
+
+ hello_tcm();
+ printk("Hello TCM executed from ITCM RAM\n");
+
+ printk("TCM variable from testrun: %u @ %p\n", tcmvar, &tcmvar);
+ tcmvar = 0xDEADBEEFU;
+ printk("TCM variable: 0x%x @ %p\n", tcmvar, &tcmvar);
+
+ printk("TCM assigned variable: 0x%x @ %p\n", tcmassigned, &tcmassigned);
+
+ printk("TCM constant: 0x%x @ %p\n", tcmconst, &tcmconst);
+
+ /* Allocate some TCM memory from the pool */
+ tcmem = tcm_alloc(20);
+ if (tcmem) {
+ printk("TCM Allocated 20 bytes of TCM @ %p\n", tcmem);
+ tcmem[0] = 0xDEADBEEFU;
+ tcmem[1] = 0x2BADBABEU;
+ tcmem[2] = 0xCAFEBABEU;
+ tcmem[3] = 0xDEADBEEFU;
+ tcmem[4] = 0x2BADBABEU;
+ for (i = 0; i < 5; i++)
+ printk("TCM tcmem[%d] = %08x\n", i, tcmem[i]);
+ tcm_free(tcmem, 20);
+ }
+}
diff --git a/Documentation/arm/vlocks.txt b/Documentation/arm/vlocks.txt
new file mode 100644
index 00000000..415960a9
--- /dev/null
+++ b/Documentation/arm/vlocks.txt
@@ -0,0 +1,211 @@
+vlocks for Bare-Metal Mutual Exclusion
+======================================
+
+Voting Locks, or "vlocks" provide a simple low-level mutual exclusion
+mechanism, with reasonable but minimal requirements on the memory
+system.
+
+These are intended to be used to coordinate critical activity among CPUs
+which are otherwise non-coherent, in situations where the hardware
+provides no other mechanism to support this and ordinary spinlocks
+cannot be used.
+
+
+vlocks make use of the atomicity provided by the memory system for
+writes to a single memory location. To arbitrate, every CPU "votes for
+itself", by storing a unique number to a common memory location. The
+final value seen in that memory location when all the votes have been
+cast identifies the winner.
+
+In order to make sure that the election produces an unambiguous result
+in finite time, a CPU will only enter the election in the first place if
+no winner has been chosen and the election does not appear to have
+started yet.
+
+
+Algorithm
+---------
+
+The easiest way to explain the vlocks algorithm is with some pseudo-code:
+
+
+ int currently_voting[NR_CPUS] = { 0, };
+ int last_vote = -1; /* no votes yet */
+
+ bool vlock_trylock(int this_cpu)
+ {
+ /* signal our desire to vote */
+ currently_voting[this_cpu] = 1;
+ if (last_vote != -1) {
+ /* someone already volunteered himself */
+ currently_voting[this_cpu] = 0;
+ return false; /* not ourself */
+ }
+
+ /* let's suggest ourself */
+ last_vote = this_cpu;
+ currently_voting[this_cpu] = 0;
+
+ /* then wait until everyone else is done voting */
+ for_each_cpu(i) {
+ while (currently_voting[i] != 0)
+ /* wait */;
+ }
+
+ /* result */
+ if (last_vote == this_cpu)
+ return true; /* we won */
+ return false;
+ }
+
+ bool vlock_unlock(void)
+ {
+ last_vote = -1;
+ }
+
+
+The currently_voting[] array provides a way for the CPUs to determine
+whether an election is in progress, and plays a role analogous to the
+"entering" array in Lamport's bakery algorithm [1].
+
+However, once the election has started, the underlying memory system
+atomicity is used to pick the winner. This avoids the need for a static
+priority rule to act as a tie-breaker, or any counters which could
+overflow.
+
+As long as the last_vote variable is globally visible to all CPUs, it
+will contain only one value that won't change once every CPU has cleared
+its currently_voting flag.
+
+
+Features and limitations
+------------------------
+
+ * vlocks are not intended to be fair. In the contended case, it is the
+ _last_ CPU which attempts to get the lock which will be most likely
+ to win.
+
+ vlocks are therefore best suited to situations where it is necessary
+ to pick a unique winner, but it does not matter which CPU actually
+ wins.
+
+ * Like other similar mechanisms, vlocks will not scale well to a large
+ number of CPUs.
+
+ vlocks can be cascaded in a voting hierarchy to permit better scaling
+ if necessary, as in the following hypothetical example for 4096 CPUs:
+
+ /* first level: local election */
+ my_town = towns[(this_cpu >> 4) & 0xf];
+ I_won = vlock_trylock(my_town, this_cpu & 0xf);
+ if (I_won) {
+ /* we won the town election, let's go for the state */
+ my_state = states[(this_cpu >> 8) & 0xf];
+ I_won = vlock_lock(my_state, this_cpu & 0xf));
+ if (I_won) {
+ /* and so on */
+ I_won = vlock_lock(the_whole_country, this_cpu & 0xf];
+ if (I_won) {
+ /* ... */
+ }
+ vlock_unlock(the_whole_country);
+ }
+ vlock_unlock(my_state);
+ }
+ vlock_unlock(my_town);
+
+
+ARM implementation
+------------------
+
+The current ARM implementation [2] contains some optimisations beyond
+the basic algorithm:
+
+ * By packing the members of the currently_voting array close together,
+ we can read the whole array in one transaction (providing the number
+ of CPUs potentially contending the lock is small enough). This
+ reduces the number of round-trips required to external memory.
+
+ In the ARM implementation, this means that we can use a single load
+ and comparison:
+
+ LDR Rt, [Rn]
+ CMP Rt, #0
+
+ ...in place of code equivalent to:
+
+ LDRB Rt, [Rn]
+ CMP Rt, #0
+ LDRBEQ Rt, [Rn, #1]
+ CMPEQ Rt, #0
+ LDRBEQ Rt, [Rn, #2]
+ CMPEQ Rt, #0
+ LDRBEQ Rt, [Rn, #3]
+ CMPEQ Rt, #0
+
+ This cuts down on the fast-path latency, as well as potentially
+ reducing bus contention in contended cases.
+
+ The optimisation relies on the fact that the ARM memory system
+ guarantees coherency between overlapping memory accesses of
+ different sizes, similarly to many other architectures. Note that
+ we do not care which element of currently_voting appears in which
+ bits of Rt, so there is no need to worry about endianness in this
+ optimisation.
+
+ If there are too many CPUs to read the currently_voting array in
+ one transaction then multiple transations are still required. The
+ implementation uses a simple loop of word-sized loads for this
+ case. The number of transactions is still fewer than would be
+ required if bytes were loaded individually.
+
+
+ In principle, we could aggregate further by using LDRD or LDM, but
+ to keep the code simple this was not attempted in the initial
+ implementation.
+
+
+ * vlocks are currently only used to coordinate between CPUs which are
+ unable to enable their caches yet. This means that the
+ implementation removes many of the barriers which would be required
+ when executing the algorithm in cached memory.
+
+ packing of the currently_voting array does not work with cached
+ memory unless all CPUs contending the lock are cache-coherent, due
+ to cache writebacks from one CPU clobbering values written by other
+ CPUs. (Though if all the CPUs are cache-coherent, you should be
+ probably be using proper spinlocks instead anyway).
+
+
+ * The "no votes yet" value used for the last_vote variable is 0 (not
+ -1 as in the pseudocode). This allows statically-allocated vlocks
+ to be implicitly initialised to an unlocked state simply by putting
+ them in .bss.
+
+ An offset is added to each CPU's ID for the purpose of setting this
+ variable, so that no CPU uses the value 0 for its ID.
+
+
+Colophon
+--------
+
+Originally created and documented by Dave Martin for Linaro Limited, for
+use in ARM-based big.LITTLE platforms, with review and input gratefully
+received from Nicolas Pitre and Achin Gupta. Thanks to Nicolas for
+grabbing most of this text out of the relevant mail thread and writing
+up the pseudocode.
+
+Copyright (C) 2012-2013 Linaro Limited
+Distributed under the terms of Version 2 of the GNU General Public
+License, as defined in linux/COPYING.
+
+
+References
+----------
+
+[1] Lamport, L. "A New Solution of Dijkstra's Concurrent Programming
+ Problem", Communications of the ACM 17, 8 (August 1974), 453-455.
+
+ http://en.wikipedia.org/wiki/Lamport%27s_bakery_algorithm
+
+[2] linux/arch/arm/common/vlock.S, www.kernel.org.